Organometallic compound and organic light-emitting device including the same

ABSTRACT

Provided are an organometallic compound and an organic light-emitting device including the same.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.10-2019-0030024, filed on Mar. 15, 2019, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND 1. Field

One or more embodiments relate to an organometallic compound and anorganic light-emitting device including the same.

2. Description of the Related Art

Organic light-emitting devices are self-emission devices that producefull-color images, and also have wide viewing angles, high contrastratios, short response times, and excellent characteristics in terms ofbrightness, driving voltage, and response speed, compared to devices inthe art.

In an example, an organic light-emitting device may include a firstelectrode disposed on a substrate, and a hole transport region, anemission layer, an electron transport region, and a second electrode,which are sequentially disposed on the first electrode. Holes providedfrom the first electrode may move toward the emission layer through thehole transport region, and electrons provided from the second electrodemay move toward the emission layer through the electron transportregion. Carriers, such as holes and electrons, recombine in the emissionlayer to produce excitons. These excitons transit from an excited stateto a ground state, thereby generating light.

SUMMARY

One or more embodiments include a novel organometallic compound and anorganic light-emitting device including the same.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

An aspect of the present disclosure provides an organometallic compoundrepresented by Formula 1:

In Formula 1,

M₁ may be selected from platinum (Pt), palladium (Pd), copper (Cu), zinc(Zn), silver (Ag), gold (Au), rhodium (Rh), iridium (Ir), ruthenium(Ru), rhenium (Re), osmium (Os), titanium (Ti), zirconium (Zr), hafnium(Hf), europium (Eu), terbium (Tb), and thulium (Tm),

ring A₁ to ring A₄ may each independently be selected from a C₅-C₆₀carbocyclic group and a C₁-C₆₀ heterocyclic group,

L₁ and L₄ may each independently be selected from a single bond, *—O—*′,*—S—*', *—C(R₅)(R₆)—*′, *—C(R₅)—*′, *—C(R₅)—*′, *—C(R₅)═C(R₆)—*′,*—C(═O)—*′, *—C(═S)—*′, *—C≡C*′, *—B(R₅)—*′, *—N(R₅)—*′, *—P(R₅)—*′,*—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′,

L₂ and L₃ may each independently be selected from *—O—*′, *—S—*′,*—C(R₅)(R₆)—*′, *—C(R₅)═*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═O)—*′,*—C(═S)—*′, *—C≡C*′, *—B(R₅)—*′, *—N(R₅)—*′, *—P(R₅)—*′,*—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′,

at least one selected from L₂ and L₃ may be selected from*—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′,and at least one pair of R₅ and R₆ selected from R₅ and R₆ in L₂ and R₅and R₆ in L₃ may be linked to form a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup,

a1 and a4 may each independently be selected from 0, 1, 2, and 3,wherein the sum of a1 and a4 may be 1 or more, when a1 is 0, ring A₁ andring A₂ are not linked with each other, and when a4 is 0, ring A₁ andring A₄ are not linked with each other,

a2 and a3 may each independently be selected from 1, 2, and 3,

Y₁ to Y₄ may each independently be selected from a carbon atom (C) and anitrogen atom (N),

B₁ to B₄ may each independently be selected from a chemical bond,*—O—*′, and *—S—*′,

R₁ to R₆ may each independently be selected from hydrogen, deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, anamidino group, a hydrazino group, a hydrazono group, a substituted orunsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, asubstituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁),—S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and —P(═S)(Q₁)(Q₂),

two neighboring substituents among R₁ to R₆ may optionally be linked toform a substituted or unsubstituted C₅-C₆₀ carbocyclic group or asubstituted or unsubstituted C₁-C₆₀ heterocyclic group,

b1 to b4 may each independently be an integer from 1 to 5,

* and *′ each indicate a binding site to a neighboring atom,

at least one substituent of the substituted C₅-C₆₀ carbocyclic group,the substituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₆₀ alkylgroup, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substitutedC₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group,the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₁-C₆₀ heteroaryl group, the substituted monovalentnon-aromatic condensed polycyclic group, and the substituted monovalentnon-aromatic condensed heteropolycyclic group may be selected from:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),—S(═O)₂(Q₁₁) and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independentlybe selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amino group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group, a biphenylgroup, and a terphenyl group.

Another aspect of the present disclosure provides an organiclight-emitting device including: a first electrode; a second electrodefacing the first electrode; an organic layer between the first electrodeand the second electrode and including an emission layer; and at leastone organometallic compound represented by Formula 1.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a schematic view of an organic light-emitting device accordingto an embodiment;

FIG. 2 is a schematic view of an organic light-emitting device accordingto another embodiment;

FIG. 3 is a schematic view of an organic light-emitting device accordingto another embodiment; and

FIG. 4 is a schematic view of an organic light-emitting device accordingto another embodiment.

DETAILED DESCRIPTION

An organometallic compound according to an embodiment is represented byFormula 1 below:

In Formula 1, M₁ may be selected from platinum (Pt), palladium (Pd),copper (Cu), zinc (Zn), silver (Ag), gold (Au), rhodium (Rh), iridium(Ir), ruthenium (Ru), rhenium (Re), osmium (Os), titanium (Ti),zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), and thulium(Tm).

In one embodiment, M₁ may be selected from Pt, Pd, Cu, Ag, and Au. Forexample, M₁ may be Pt.

In Formula 1, ring A₁ to ring A₄ may each independently be selected froma C₅-C₆₀ carbocyclic group and a C₁-C₆₀ heterocyclic group.

In one embodiment, ring A₁ to ring A₄ in Formula 1 may eachindependently be selected from a benzene group, a naphthalene group, ananthracene group, a phenanthrene group, an azulene group, a triphenylenegroup, a pyrene group, a chrysene group, a cyclopentadiene group, a1,2,3,4-tetrahydronaphthalene group, a furan group, a thiophene group, asilole group, an indene group, a fluorene group, an indole group, acarbazole group, a benzofuran group, a dibenzofuran group, abenzothiophene group, a dibenzothiophene group, a benzosilole group, adibenzosilole group, an indenopyridine group, an indolopyridine group, abenzofuropyridine group, a benzothienopyridine group, abenzosilolopyridine group, an indenopyrimidine group, anindolopyrimidine group, a benzofuropyrimidine group, abenzothienopyrimidine group, a benzosilolopyrimidine group, adihydropyridine group, a pyridine group, a pyrimidine group, a pyrazinegroup, a pyridazine group, a triazine group, a quinoline group, anisoquinoline group, a quinoxaline group, a quinazoline group, aphenanthroline group, a pyrrole group, a pyrazole group, an imidazolegroup, a 2,3-dihydroimidazole group, a triazole group, a2,3-dihydrotriazole group, an oxazole group, an isoxazole group, athiazole group, an isothiazole group, an oxadiazole group, a thiadiazolegroup, a benzopyrazole group, a pyrazolopyridine group, a furopyrazolegroup, a thienopyrazole group, a benzimidazole group, a2,3-dihydrobenzimidazole group, an imidazopyridine group, a2,3-dihydroimidazopyridine group, a furoimidazole group, athienoimidazole group, an imidazopyrimidine group, a2,3-dihydroimidazopyrimidine group, an imidazopyrazine group, a2,3-dihydroimidazopyrazine group, a benzoxazole group, a benzothiazolegroup, a benzoxadiazole group, a benzothiadiazole group, a5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinolinegroup.

In one embodiment, in Formula 1, ring A₃ may be a 6-membered ringincluding one or more N atoms, and one selected from ring A₁, ring A₂,and ring A₄ may be a 5-membered ring including two or more N atoms.

In one or more embodiments, in Formula 1, ring A₃ may be a 6-memberedring including one or more N atoms, and one selected from ring A₁ andring A₂ may be a 5-membered ring including two or more N atoms.

In one or more embodiments, in Formula 1, ring A₃ may be a 6-memberedring including one or more N atoms, and Y₃ may be N. For example, ringA₃ may be a pyridine group.

In one embodiment, in Formula 1, ring A₃ may be a group which isrepresented by Formula 2-2(1) and in which Y₁₅ is N,

ring A₁, ring A₂, and ring A₄ may each independently be selected fromgroups represented by Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25):

In Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25),

Y₁₅ may be a carbon atom (C) or a nitrogen atom (N),

X₂₁ may be N or C(R₂₁), X₂₂ may be N or C(R₂₂), X₂₃ may be N or C(R₂₃),X₂₄ may be N or C(R₂₄), X₂₅ may be N or C(R₂₅), X₂₆ may be N or C(R₂₆),X₂₇ may be N or C(R₂₇), and X₂₈ may be N or C(R₂₈),

X₂₉ may be C(R_(29a))(R_(29b)), Si(R_(29a))(R_(29b)), N(R₂₉), O, or S,

X₃₀ may be C(R_(30a))(R_(30b)), Si(R_(30a))(R_(30b)), N(R₃₀), O, or S,

R₂₁ to R₃₀ and R_(25a) to R_(30b) may each independently be the same asdefined in connection with R₁ to R₄ in Formula 1,

* indicates a binding site to B₁, B₂, B₃, or B₄, and

*′ and *″ each indicate a binding site to a neighboring atom.

In one embodiment, in Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25),R₂₁ to R₃₀ and R_(25a) to R_(30b) may each independently be selectedfrom:

hydrogen, deuterium, —F, —Cl, —Br, —I, a cyano group, a C₁-C₂₀ alkylgroup, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a cyano group, aphenyl group, and a biphenyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a phenanthrenyl group, ananthracenyl group, a pyridinyl group, a pyrimidinyl group, a carbazolylgroup, and a triazinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a phenanthrenyl group, ananthracenyl group, a pyridinyl group, a pyrimidinyl group, a carbazolylgroup, and a triazinyl group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a cyano group, a phenylgroup, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a phenanthrenyl group, ananthracenyl group, a pyridinyl group, a pyrimidinyl group, a carbazolylgroup, and a triazinyl group.

For example, in Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25), R₂₁ toR₃₀ and R_(25a) to R_(30b) may each independently be selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a cyano group, a methyl group, anethyl group, a propyl group, an isopropyl group, an n-butyl group, anisobutyl group, a sec-butyl group, a tert-butyl group, a phenyl group,and a pyridinyl group.

In one embodiment, in Formula 1, a4 may be 0, ring A₁ and ring A₄ mayeach independently be selected from groups represented by Formulae2-1(1) to 2-1(35), ring A₂ may be selected from groups represented byFormulae 2-2(1) to 2-2(25), ring A₃ may be a group which is representedby Formula 2-2(1) and in which Y₁₅ is N.

For example, in Formula 1, a4 may be 0, ring A₁ may be a grouprepresented by Formula 2-1(32), ring A₂ may be a group represented byFormula 2-2(1), ring A₃ may be a group which is represented by Formula2-2(1) and in which Y₁₅ is N, and ring A₄ ring may be a grouprepresented by Formula 2-1(1).

In one embodiment, in Formula 1, a4 may be 0, ring A₁ and ring A₄ mayeach independently be a group represented by Formula 2-1(1), ring A₂ maybe a group represented by Formula 2-2(10), 2-2(12), or 2-2(20), and ringA₃ may be a group which is represented by Formula 2-2(1) and in whichY₁₅ is N.

In Formula 1, L₁ and L₄ may each independently be selected from a singlebond, *—O—*′, *—S—*′, *—C(R₅)(R₆)—*′, *—C(R₅)═*′, *═C(R₅)—*′,*—C(R₅)═C(R₆)—*′, *—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′, *—B(R₅)—*′,*—N(R₅)—*′, *—P(R₅)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and*—Ge(R₅)(R₆)—*′, and

L₂ and L₃ may each independently be selected from *—O—*′, *—S—*′,*—C(R₅)(R₆)—*′, C(R₅)═*′, *═C(R₅)—*′, *—C(R₅)≡C(R₆)—*′, *—C(═O)—*′,*—C(═S)—*′, *—C≡C—*′, *—B(R₅)—*′, *—N(R₅)—*′, *—P(R₅)—*′,*—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′, wherein at leastone selected from L₂ and L₃ may be selected from *—C(R₅)(R₆)—*′,*—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′.

When at least one selected from L₂ and L₃ is selected from*—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′, atleast one pair of R₅ and R₆ selected from R₅ and R₆ in L₂ and R₅ and R₆in L₃ may be linked to form a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup.

That is, when L₂ is selected from *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′,*—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′ and L₃ is selected from *—O—*′,*—S—*′, *—C(R₅)═*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═O)—*′,*—C(═S)—*′, *—C≡C—*′, *—B(R₅)—*′, *—N(R₅)—*′, and *—P(R₅)—*′, R₅ and R₆in L₂ may be linked to form a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup,

when L₃ is selected from *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′,*—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′ and L₂ is selected from *—O—*′,*—S—*′, *—C(R₅)═*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═O)—*′,*—C(═S)—*′, *—C≡C—*′, *—B(R₅)—*′, *—N(R₅)—*′, and *—P(R₅)—*′, R₅ and R₆in L₃ may be linked to form a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup, and

when L₂ and L₃ are each independently selected from *—C(R₅)(R₆)—*′,*—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′, at least one pairof R₅ and R₆ selected from R₅ and R₆ in L₂ and R₅ and R₆ in L₃ may belinked to form a substituted or unsubstituted C₅-C₆₀ carbocyclic groupor a substituted or unsubstituted C₁-C₆₀ heterocyclic group.

In Formula 1, a1 and a4 may each independently be selected from 0, 1, 2,and 3, wherein the sum of a1 and a4 is 1 or more. When a1 is 0, ring A₁and ring A₂ are not linked with each other, and when a4 is 0, ring A₁and ring A₄ are not linked with each other.

a1 indicates the number of L₁, wherein, when a1 is two or more, aplurality of L₁(s) may be identical to or different from each other.When L₁ is a single bond, ring A₁ and ring A₂ may be directly linkedwith each other.

a4 indicates the number of L₄, wherein, when a4 is two or more, aplurality of L₂(s) may be identical to or different from each other.When L₄ is a single bond, ring A₁ and ring A₄ may be directly linkedwith each other.

In one embodiment, the sum of a1 and a4 in Formula 1 may be 1. That is,a1 may be 1, and a4 may be 0; or a1 may be 0, and a4 may be 1.

For example, a1 may be 1, and a4 may be 0.

In Formula 1, a2 and a3 may each independently be selected from 1, 2,and 3.

a2 indicates the number of L₂, wherein, when a2 is 2 or more, aplurality of L₂(s) may be identical to or different from each other. a3indicates the number of L₃, wherein, when a3 is 2 or more, a pluralityof L₃(s) may be identical to or different from each other.

In one embodiment, in Formula 1, i) a2 and a3 may each be 1, L₂ may beselected from *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and*—Ge(R₅)(R₆)—*′, L₃ may be selected from *—O—*′, *—S—*′, *—C(R₅)(R₆)—*′,and *—N(R₅)—*′, and R₅ and R₆ in L₂ may be linked to form a substitutedor unsubstituted C₅-C₆₀ carbocyclic group or a substituted orunsubstituted C₁-C₆₀ heterocyclic group;

ii) a2 and a3 may each be 1, L₂ may be selected from *—O—*′, *—S—*′,*—C(R₅)(R₆)—*′, and *—N(R₅)—*′, L₃ may be selected from *—C(R₅)(R₆)—*′,*—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′, and R₅ and R₆ inL₃ may be linked to form a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup; or

iii) a2 and a3 may each be 1, L₂ and L₃ may each independently beselected from *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and*—Ge(R₅)(R₆)—*′, and at least one pair of R₅ and R₆ selected from R₅ andR₆ in L₂ and R₅ and R₆ in L₃ may be linked to form a substituted orunsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstitutedC₁-C₆₀ heterocyclic group.

In one embodiment, in Formula 1, at least one selected from L₂ and L₃may be selected from *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′,and *—Ge(R₅)(R₆)—*′, and at least one pair of R₅ and R₆ selected from R₅and R₆ in L₂ and R₅ and R₆ in L₃ may be linked to form a grouprepresented by Formula 3:

In Formula 3,

X₃₁ may be selected from a single bond, *—O—*′, *—S—*′, *—Se—*′,*—C(R₃₃)(R₃₄)—*, *—C(R₃₃)═C(R₃₄)—*′, *—Si(R₃₃)(R₃₄)—*′, and*—Ge(R₃₃)(R₃₄)—*′,

A₃₁ and A₃₂ may each independently be selected from a C₆-C₃₀ carbocyclicgroup and a C₁-C₃₀ heterocyclic group,

R₃₁ to R₃₄ may each independently be selected from hydrogen, deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, anamidino group, a hydrazino group, a hydrazono group, a substituted orunsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, asubstituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and—P(═O)(Q₁)(Q₂),

Q₁ to Q₃ may each independently be selected from hydrogen, deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, anamidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkylgroup, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxygroup, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, aC₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromaticcondensed polycyclic group, a monovalent non-aromatic condensedheteropolycyclic group, a biphenyl group, and a terphenyl group,

b31 and b32 may each independently be selected from 1, 2, 3, 4, 5, and6, and

* indicates a binding site to C, Si, P, or Ge.

In one or more embodiments, at least one selected from L₂ and L₃ inFormula 1 may be selected from *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′,*—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′, wherein a pair of R₅ and R₆selected from R₅(s) in the number of L₂ and R₆(s) in the number L₃ maybe linked with each other to form a group represented by Formula 3A:

In Formula 3A,

X₃₁ and R₃₁ to R₃₄ may each independently be the same as defined inconnection with Formula 3,

b31 and b32 may each independently be selected from 1, 2, 3, and 4, and

* indicates a binding site to C, Si, P, or Ge.

In one embodiment, in Formulae 3 and 3A, R₃₁ to R₃₄ may eachindependently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a cyano group, a C₁-C₂₀ alkylgroup, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a cyano group, aphenyl group, and a biphenyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a phenanthrenyl group, ananthracenyl group, a pyridinyl group, a pyrimidinyl group, a carbazolylgroup, and a triazinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a phenanthrenyl group, ananthracenyl group, a pyridinyl group, a pyrimidinyl group, a carbazolylgroup, and a triazinyl group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a cyano group, a phenylgroup, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a phenanthrenyl group, ananthracenyl group, a pyridinyl group, a pyrimidinyl group, a carbazolylgroup, and a triazinyl group.

For example, R₃₁ to R₃₄ in Formulae 3 and 3A may each independently beselected from hydrogen, deuterium, —F, —Cl, —Br, —I, a cyano group, amethyl group, an ethyl group, a propyl group, an isopropyl group, ann-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group,a phenyl group, and a pyridinyl group.

In Formula 1, Y₁ to Y₄ may each independently be selected from a carbonatom (C) and a nitrogen atom (N).

In one embodiment, i) Y₁, Y₂, and Y₄ may each be C, and Y₃ may be N; ii)Y₁ and Y₂ may each be C, and Y₃ and Y₄ may each be N; iii) Y₁ and Y₄ mayeach be C, and Y₂ and Y₃ may each be N; or iv) Y₂ and Y₄ may each be C,and Y₁ and Y₃ may each be N.

For example, i) Y₁, Y₂, and Y₄ may each be C, and Y₃ may be N; or ii) Y₁and Y₄ may each be C, and Y₂ and Y₃ may each be N.

In one embodiment, each of B₁ to B₄ may be a chemical bond, Y₃ may be N,and a bond between Y₃ and M₁ may be a coordinate bond,

i) Y₁, Y₂, and Y₄ may each be C, one bond selected from a bond betweenY₁ and M₁, a bond between Y₂ and M₁, and a bond between Y₄ and M₁ may bea coordinate bond, and the others thereof may be a covalent bond;

ii) Y₁ and Y₄ may each be C, Y₂ may be N, a bond between Y₂ and M₁ maybe a coordinate bond, and a bond between Y₁ and M₁ and a bond between Y₄and M₁ may be a covalent bond; or

iii) Y₁ may be N, Y₂ and Y₄ may each be C, a bond between Y₁ and M₁ maybe a coordinate bond, and a bond between Y₂ and M₁ and a bond between Y₄and M₁ may be a covalent bond.

In Formula 1, B₁ to B₄ may each independently be selected from achemical bond, *—O—*′, and *—S—*′.

When B₁ is a chemical bond, Y₁ and M₁ may be directly linked with eachother, when B₂ is a chemical bond, Y₂ and M₁ may be directly linked witheach other, when B₃ is a chemical bond, Y₃ and M₁ may be directly linkedwith each other, and when B₄ is a chemical bond, Y₄ and M₁ may bedirectly linked with each other.

In one embodiment, in Formula 1, i) each of B₁ to B₄ may be a chemicalbond; or ii) at least one selected from B₁ to B₄ may be *—O—*′ or*—S—*′, and the others thereof may be a chemical bond.

For example, each of B₁ to B₄ may be a chemical bond. In one embodiment,each of B₁ to B₃ may be a chemical bond, and B₄ may be *—O—*′.

In Formula 1, R₁ to R₆ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, asubstituted or unsubstituted C₁-C₆₀ alkyl group, a substituted orunsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstitutedC₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxygroup, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂),—P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and—P(═S)(Q₁)(Q₂),

two neighboring substituents among R₁ to R₆ may optionally be linked toform a substituted or unsubstituted C₅-C₆₀ carbocyclic group or asubstituted or unsubstituted C₁-C₆₀ heterocyclic group.

In one embodiment, R₁ to R₆ may each independently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a cyano group, a C₁-C₂₀ alkylgroup, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a cyano group, aphenyl group, and a biphenyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a phenanthrenyl group, ananthracenyl group, a pyridinyl group, a pyrimidinyl group, a carbazolylgroup, and a triazinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a phenanthrenyl group, ananthracenyl group, a pyridinyl group, a pyrimidinyl group, a carbazolylgroup, and a triazinyl group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a cyano group, a phenylgroup, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a phenanthrenyl group, ananthracenyl group, a pyridinyl group, a pyrimidinyl group, a carbazolylgroup, and a triazinyl group.

In one or more embodiments, R₁ to R₆ may each independently be selectedfrom hydrogen, deuterium, —F, —Cl, —Br, —I, a cyano group, a methylgroup, an ethyl group, a propyl group, an isopropyl group, an n-butylgroup, an isobutyl group, a sec-butyl group, a tert-butyl group, aphenyl group, and a pyridinyl group.

In Formula 1, b1 to b4 may each independently be an integer from 1 to 5.

b1 indicates the number of R₁, wherein, when b1 is two or more, two ormore R₁(s) may be identical to or different from each other.

b2 indicates the number of R₂, wherein, when b2 is two or more, two ormore R₂(s) may be identical to or different from each other.

b3 indicates the number of R₃, wherein, when b3 is two or more, two ormore R₃(s) may be identical to or different from each other.

b4 indicates the number of R₄, wherein, when b4 is two or more, two ormore R₄(s) may be identical to or different from each other.

In the description regarding Formula 1, * and *′ each indicate a bindingsite to a neighboring atom.

In the description regarding Formula 1, at least one substituent of thesubstituted C₅-C₆₀ carbocyclic group, the substituted C₁-C₆₀heterocyclic group, the substituted C₁-C₆₀ alkyl group, the substitutedC₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, thesubstituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkylgroup, the substituted C₁-C₁₀ heterocycloalkyl group, the substitutedC₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenylgroup, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxygroup, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀heteroaryl group, the substituted monovalent non-aromatic condensedpolycyclic group, and the substituted monovalent non-aromatic condensedheteropolycyclic group may be selected from:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),—S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independentlybe selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amino group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group, a biphenylgroup, and a terphenyl group.

In one embodiment, the organometallic compound may be represented by oneof Formulae 1-1 to 1-3:

In Formulae 1-1 to 1-3,

L₂ and L₃ may each independently be selected from *—O—*′, *—S—*′,*—C(R₅)(R₆)—*′, *—C(R₅)═*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═O)—*′,*—C(═S)—*′, *—C≡C—*′, *—B(R₅)—*′, *—N(R₅)—*′, *—P(R₅)—*′,*—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′,

X₁ and X₂ may each independently be selected from C, Si, P, and Ge,

X₂₂ may be N or C(R₂₂), X₂₃ may be N or C(R₂₃), and X₂₄ may be N orC(R₂₄),

X₃₁ may be selected from a single bond, *—O—*′, *—S—*′, *—Se—*′,*—C(R₃₃)(R₃₄)—*, *—C(R₃₃)═C(R₃₄)—*′, *—Si(R₃₃)(R₃₄)—*′, and*—Ge(R₃₃)(R₃₄)—*′,

X₃₂ may be selected from a single bond, *—O—*′, *—S—*′, *—Se—*′,*—C(R₃₇)(R₃₈)—*, *—C(R₃₇)═C(R₃₈)—*′, *—Si(R₃₇)(R₃₈)—*′ and*—Ge(R₃₇)(R₃₈)—*′,

R₂₂ to R₂₄ may each independently be the same as defined in connectionwith R₃ in Formula 1, R₃₁ to R₃₄ may each independently be the same asdescribed above, and R₃₅ to R₃₈ may each independently be the same asdefined in connection with R₃₁ to R₃₄ in Formula 3,

b31, b32, b35, and b36 may each independently be selected from 1, 2, 3,and 4,

M₁, ring A₁, ring A₂, ring A₄, L₁, L₄, a1, a4, Y₁ to Y₄, B₁ to B₄, R₁,R₂, R₄, b1, b2, and b4 may each independently be the same as defined inconnection with Formula 1.

In one embodiment, in Formulae 1-1 to 1-3,

i) L₂ and L₃ may each independently be selected from *—O—*′, *—S—*′,*—C(R₅)(R₆)—*′, and *—N(R₅)—*′;

ii) L₂ may be *—N(R₅)—*′, and R₅ may be linked with neighboring R₂ orR₂₂; or

iii) L₃ may be *—N(R₅)—*′, and R₅ may be linked with neighboring R₄ orR₂₄.

In one embodiment, in Formulae 1-1 to 1-3, X₂₂ may be C(R₂₂), X₂₃ may beC(R₂₃), and X₂₄ may be C(R₂₄). For example, X₂₂ may be C(R₂₂), X₂₃ maybe C(R₂₃), X₂₄ may be C(R₂₄), R₂₂ and R₂₄ may be hydrogen, and R₂₃ maybe hydrogen or a tert-butyl group.

In one or more embodiments, in Formulae 1-1 to 1-3, X₂₂ may be C(R₂₂),X₂₃ may be C(R₂₃), X₂₄ may be C(R₂₄), and at least one selected from R₂₂to R₂₄, R₃₁, R₃₂, R₃₅, and R₃₆ may not be hydrogen.

In one or more embodiments, the organometallic compound may berepresented by one of Formulae 1-1A to 1-3A:

In Formulae 1-1A to 1-3A,

L₂, L₃, X₁, X₂, X₂₂ to X₂₄, R₃₁, R₃₂, R₃₅, R₃₆, b31, b32, b35, and b36may each independently be the same as defined in connection withFormulae 1-1 to 1-3, and

M₁, ring A₁, ring A₂, ring A₄, L₁, L₄, a1, a4, Y₁ to Y₄, B₁ to B₄, R₁,R₂, R₄, b1, b2, and b4 may each independently be the same as defined inconnection with Formula 1.

In one embodiment, in Formulae 1-1A to 1-3A,

i) L₂ and L₃ may each independently be selected from *—O—*′, *—S—*′,*—C(R₅)(R₆)—*′, and *—N(R₅)—*′;

ii) L₂ may be *—N(R₅)—*′, and R₅ may be linked with neighboring R₂ orR₂₂; or

iii) L₃ may be *—N(R₅)—*′, and R₅ may be linked with neighboring R₄ orR₂₄.

In one embodiment, in Formulae 1-1A to 1-3A, X₂₂ may be C(R₂₂), X₂₃ maybe C(R₂₃), and X₂₄ may be C(R₂₄). For example, X₂₂ may be C(R₂₂), X₂₃may be C(R₂₃), X₂₄ may be C(R₂₄), R₂₂ and R₂₄ may be hydrogen, and R₂₃may be hydrogen or a tert-butyl group.

In one or more embodiments, in Formulae 1-1A to 1-3A, X₂₂ may be C(R₂₂),X₂₃ may be C(R₂₃), X₂₄ may be C(R₂₄), and at least one selected from R₂₂to R₂₄, R₃₁, R₃₂, R₃₅, and R₃₆ may not be hydrogen.

In one embodiment, the organometallic compound represented by Formula 1may be one selected from Compounds 1 to 40:

In the organometallic compound represented by Formula 1, ring A₃ islinked to ring A₂ and ring A₄ via linkers L₂ and L₃, thereby increasingthe rigidity of ring A₃. In addition, in the organometallic compoundrepresented by Formula 1, bond dissociation energy of a metal center M₁and ring A₃ may be increased, as compared with an organometallic complexincluding an organic ligand in which one of linkers L₂ and L₃ does notexist (that is, an organic ligand with which ring A₂ and ring A₃ are notlinked, or ring A₃ and ring A₄ are not linked). Accordingly, thestability in the ground state of the organometallic compound may beincreased, thereby improving the lifespan thereof. Therefore, thedurability of the organic light-emitting device to which theorganometallic compound is applied may be increased, thereby improvingthe lifespan thereof.

Furthermore, since the organometallic compound represented by Formula 1has a high energy level of a triplet metal-centered state (³MC state),the stability of the compound in the excited state may be improved.Therefore, since a non-radiative decay phenomenon is reduced, when theorganometallic compound is applied to an electronic device, for example,an organic light-emitting device, the device may have a long lifespan.

Furthermore, at least one selected from the linkers L₂ and L₃ isselected from *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and*—Ge(R₅)(R₆)—*′. The at least one selected from the linkers L₂ and L₃includes a ring structure in which R₅ and R₆ bonded to an atom (C, Si,P, or Ge) in the linkers are linked via a single bond or a linkinggroup. This ring structure causes steric hindrance in the organometalliccompound represented by Formula 1. When the organometallic compound isapplied to an emission layer dopant of the organic light-emittingdevice, it may hinder the formation of excimer or exciplex due to aninteraction between the dopants or between the dopant and the host.Therefore, it is possible to maintain high efficiency and color purityduring the driving of the device.

A synthesis method for the organometallic compound represented byFormula 1 would be apparent to those of ordinary skill in the art byreferring to the following examples.

The organometallic compound represented by Formula 1 may be used betweena pair of electrodes of an organic light-emitting device. For example,the organometallic compound may be included in an emission layer. Theorganometallic compound may act as a dopant in the emission layer. Inone or more embodiments, the organometallic compound of Formula 1 may beused as a material for a capping layer located outside a pair ofelectrodes of an organic light-emitting device.

Accordingly, there is provided an organic light-emitting deviceincluding: a first electrode; a second electrode facing the firstelectrode; an organic layer between the first electrode and the secondelectrode; and at least one organometallic compound represented byFormula 1.

In one embodiment, the organic layer of the organic light-emittingdevice may include the at least one organometallic compounds representedby Formula 1.

The expression “(an organic layer) includes at least one organometalliccompounds” used herein may include a case in which “(an organic layer)includes identical organometallic compounds represented by Formula 1”and a case in which “(an organic layer) includes two or more differentorganometallic compounds represented by Formula 1”.

For example, the organic layer may include, as the organometalliccompound, only Compound 1. In this regard, Compound 1 may exist only inthe emission layer of the organic light-emitting device. In one or moreembodiments, the organic layer may include, as the organometalliccompound, Compound 1 and Compound 2. In this regard, Compound 1 andCompound 2 may exist in an identical layer (for example, Compound 1 andCompound 2 may all exist in an emission layer), or different layers (forexample, Compound 1 may exist in an emission layer and Compound 2 mayexist in an electron transport region).

In one embodiment, the first electrode may be an anode, and the secondelectrode may be a cathode, and the organic layer may include theorganometallic compound, and may further include a hole transport regionbetween the first electrode and the emission layer and an electrontransport region between the emission layer and the second electrode.The hole transport region may include a hole injection layer, a holetransport layer, an emission auxiliary layer, an electron blockinglayer, or any combination thereof. The electron transport regionincludes a buffer layer, a hole blocking layer, an electron controllayer, an electron transport layer, an electron injection layer, or anycombination thereof.

In one or more embodiments, the emission layer of the organiclight-emitting device may include the at least one organometalliccompound.

In one or more embodiments, the emission layer of the organiclight-emitting device may include the at least one organometalliccompound, the emission layer may further include a host, and an amountof the host included in the emission layer may be larger than an amountof the organometallic compound included in the emission layer. Forexample, the amount of the organometallic compound may be in a range ofabout 0.01 parts by weight to about 30 parts by weight based on 100parts by weight of the emission layer.

In one embodiment, the emission layer may include the organometalliccompound, and the emission layer may emit blue light or green light. Forexample, the emission layer may emit blue light or green light having awavelength of maximum emission in a range of about 400 nm or more andabout 600 nm or less, for example, a wavelength of maximum emission in arange of about 460 nm or more and about 570 nm or less. The wavelengthof maximum emission of the organometallic compound is a value obtainedthrough quantum simulation using a density functional theory (DFT)calculation method.

In one embodiment, the hole transport region may include an electronblocking layer, and the electron blocking layer may include theorganometallic compound; or the electron transport region may include ahole blocking layer, and the hole blocking layer may include theorganometallic compound.

In one embodiment, the hole transport region may include a p-dopanthaving a lowest unoccupied molecular orbital (LUMO) energy level of −3.5eV or less.

In one embodiment, the electron transport region may include a phosphineoxide-containing compound and/or a silyl-containing compound. Forexample, the electron transport region may include a hole blockinglayer, the hole blocking layer may directly contact the emission layer,and the hole blocking layer may include the phosphine oxide-containingcompound and/or a silyl-containing compound.

The term “an organic layer” as used herein refers to a single layerand/or a plurality of layers disposed between the first electrode andthe second electrode of an organic light-emitting device. A materialincluded in the “organic layer” is not limited to an organic material.

[Description of FIG. 1]

FIG. 1 is a schematic cross-sectional view of an organic light-emittingdevice 10 according to an embodiment. The organic light-emitting device10 includes a first electrode 110, an organic layer 150, and a secondelectrode 190.

Hereinafter, the structure of the organic light-emitting device 10according to an embodiment and a method of manufacturing the organiclight-emitting device 10 will be described in connection with FIG. 1.

[First Electrode 110]

In FIG. 1, a substrate may be additionally disposed under the firstelectrode 110 or above the second electrode 190. The substrate may be aglass substrate or a plastic substrate, each having excellent mechanicalstrength, thermal stability, transparency, surface smoothness, ease ofhandling, and water resistance.

The first electrode 110 may be formed by depositing or sputtering amaterial for forming the first electrode 110 on the substrate. When thefirst electrode 110 is an anode, the material for forming the firstelectrode 110 may be selected from materials with a high work functionto facilitate hole injection.

The first electrode 110 may be a reflective electrode, a semi-reflectiveelectrode, or a transmissive electrode. When the first electrode 110 isa transmissive electrode, a material for forming a first electrode maybe selected from indium tin oxide (ITO), indium zinc oxide (IZO), tinoxide (SnO₂), zinc oxide (ZnO), and any combinations thereof, butembodiments of the present disclosure are not limited thereto. In one ormore embodiments, when the first electrode 110 is a semi-transmissiveelectrode or a reflectable electrode, a material for forming a firstelectrode may be selected from magnesium (Mg), silver (Ag), aluminum(Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In),magnesium-silver (Mg—Ag), and any combinations thereof, but embodimentsof the present disclosure are not limited thereto.

The first electrode 110 may have a single-layered structure, or amulti-layered structure including two or more layers. For example, thefirst electrode 110 may have a three-layered structure of ITO/Ag/ITO,but the structure of the first electrode 110 is not limited thereto.

[Organic Layer 150]

The organic layer 150 may be disposed on the first electrode 110. Theorganic layer 150 may include an emission layer.

The organic layer 150 may further include a hole transport regionbetween the first electrode 110 and the emission layer and an electrontransport region between the emission layer and the second electrode190.

[Hole Transport Region in Organic Layer 150]

The hole transport region may have i) a single-layered structureincluding a single layer including a single material, ii) asingle-layered structure including a single layer including a pluralityof different materials, or iii) a multi-layered structure having aplurality of layers including a plurality of different materials.

The hole transport region may include at least one layer selected from ahole injection layer, a hole transport layer, an emission auxiliarylayer, and an electron blocking layer.

For example, the hole transport region may have a single-layeredstructure including a single layer including a plurality of differentmaterials, or a multi-layered structure having a hole injectionlayer/hole transport layer structure, a hole injection layer/holetransport layer/emission auxiliary layer structure, a hole injectionlayer/emission auxiliary layer structure, a hole transportlayer/emission auxiliary layer structure, or a hole injection layer/holetransport layer/electron blocking layer structure. For each structure,constituting layers are sequentially stacked from the first electrode110 in this stated order, but the structure of the hole transport regionis not limited thereto.

The hole transport region may include at least one selected fromm-MTDATA, TDATA, 2-TNATA, NPB (NPD), β-NPB, TPD, spiro-TPD, spiro-NPB,methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine(TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphor sulfonic acid (PANI/CSA),polyaniline/poly(4-styrenesulfonate) (PANI/PSS), a compound representedby Formula 201, and a compound represented by Formula 202:

In Formulae 201 and 202,

L₂₀₁ to L₂₀₄ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

L₂₀₅ may be selected from *—O—*′, *—S—*′, *—N(Q₂₀₁)—*′, a substituted orunsubstituted C₁-C₂₀ alkylene group, a substituted or unsubstitutedC₂-C₂₀ alkenylene group, a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xa1 to xa4 may each independently be an integer from 0 to 3,

xa5 may be an integer from 1 to 10,

R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from asubstituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted orunsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group.

For example, in Formula 202, R₂₀₁ and R₂₀₂ may optionally be linked viaa single bond, a dimethyl-methylene group, or a diphenyl-methylenegroup, and R₂₀₃ and R₂₀₄ may optionally be linked via a single bond, adimethyl-methylene group, or a diphenyl-methylene group.

In one embodiment, in Formulae 201 and 202,

L₂₀₁ to L₂₀₅ may each independently be selected from:

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anindacenylene group, an acenaphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenalenylene group, a phenanthrenylenegroup, an anthracenylene group, a fluoranthenylene group, atriphenylenylene group, a pyrenylene group, a chrysenylene group, anaphthacenylene group, a picenylene group, a perylenylene group, apentaphenylene group, a hexacenylene group, a pentacenylene group, arubicenylene group, a coronenylene group, an ovalenylene group, athiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group; and

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anindacenylene group, an acenaphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenalenylene group, a phenanthrenylenegroup, an anthracenylene group, a fluoranthenylene group, atriphenylenylene group, a pyrenylene group, a chrysenylene group, anaphthacenylene group, a picenylene group, a perylenylene group, apentaphenylene group, a hexacenylene group, a pentacenylene group, arubicenylene group, a coronenylene group, an ovalenylene group, athiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group,a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

In one or more embodiments, xa1 to xa4 may each independently be 0, 1,or 2.

In one or more embodiments, xa5 may be 1, 2, 3, or 4.

In one or more embodiments, R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independentlybe selected from:

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group,an indenyl group, a naphthyl group, an azulenyl group, a heptalenylgroup, an indacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a naphthacenyl group, a picenyl group, a perylenylgroup, a pentaphenyl group, a hexacenyl group, a pentacenyl group, arubicenyl group, a coronenyl group, an ovalenyl group, a thiophenylgroup, a furanyl group, a carbazolyl group, an indolyl group, anisoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group,an indenyl group, a naphthyl group, an azulenyl group, a heptalenylgroup, an indacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a naphthacenyl group, a picenyl group, a perylenylgroup, a pentaphenyl group, a hexacenyl group, a pentacenyl group, arubicenyl group, a coronenyl group, an ovalenyl group, a thiophenylgroup, a furanyl group, a carbazolyl group, an indolyl group, anisoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ are the same as described above.

In one or more embodiments, at least one selected from R₂₀₁ to R₂₀₃ inFormula 201 may each independently be selected from:

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group; and

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, acyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkylgroup, a phenyl group substituted with —F, a naphthyl group, a fluorenylgroup, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranylgroup, and a dibenzothiophenyl group,

but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, in Formula 202, i) R₂₀₁ and R₂₀₂ may belinked via a single bond, and/or ii) R₂₀₃ and R₂₀₄ may be linked via asingle bond.

In one or more embodiments, at least one selected from R₂₀₁ to R₂₀₄ inFormula 202 may be selected from:

a carbazolyl group; and

a carbazolyl group substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, acarbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group,

but embodiments of the present disclosure are not limited thereto.

The compound represented by Formula 201 may be represented by Formula201A:

In one embodiment, the compound represented by Formula 201 may berepresented by Formula 201A(1) below, but embodiments of the presentdisclosure are not limited thereto:

In one embodiment, the compound represented by Formula 201 may berepresented by Formula 201A-1 below, but embodiments of the presentdisclosure are not limited thereto:

In one embodiment, the compound represented by Formula 202 may berepresented by Formula 202A:

In one embodiment, the compound represented by Formula 202 may berepresented by Formula 202A-1:

In Formulae 201A, 201A(1), 201A-1, 202A, and 202A-1,

L₂₀₁ to L_(203,) xa1 to xa3, xa5, and R₂₀₂ to R₂₀₄ may be understood byreferring to corresponding description presented herein,

R₂₁₁ and R₂₁₂ may each independently be the same as defined inconnection with R₂₀₃, and

R₂₁₃ to R₂₁₇ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group.

The hole transport region may include at least one compound selectedfrom Compounds HT1 to HT39, but embodiments of the present disclosureare not limited thereto:

A thickness of the hole transport region may be from about 100 Å toabout 10,000 Å, for example, about 100 Å to about 3,000 Å. When the holetransport region includes at least one selected from a hole injectionlayer and a hole transport layer, a thickness of the hole injectionlayer may be in a range of about 100 Å to about 9,000 Å, for example,about 100 Å to about 1,000 Å, and a thickness of the hole transportlayer may be in a range of about 50 Å to about 2,000 Å, for exampleabout 100 Å to about 1,500 Å. When the thicknesses of the hole transportregion, the hole injection layer, and the hole transport layer arewithin these ranges, satisfactory hole transporting characteristics maybe obtained without a substantial increase in driving voltage.

The emission auxiliary layer may increase light-emission efficiency bycompensating for an optical resonance distance according to thewavelength of light emitted by an emission layer, and the electronblocking layer may block the flow of electrons from an electrontransport region. The emission auxiliary layer and the electron blockinglayer may include the materials as described above.

[p-Dopant]

The hole transport region may further include, in addition to thesematerials, a charge-generation material for the improvement ofconductive properties. The charge-generation material may behomogeneously or non-homogeneously dispersed in the hole transportregion.

The charge-generation material may be, for example, a p-dopant.

In one embodiment, the p-dopant may have a LUMO energy level of −3.5 eVor less.

The p-dopant may include at least one selected from a quinonederivative, a metal oxide, and a cyano group-containing compound, butembodiments of the present disclosure are not limited thereto.

In one embodiment, the p-dopant may include at least one selected from:

a quinone derivative, such as tetracyanoquinodimethane (TCNQ) and2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ);

a metal oxide, such as tungsten oxide or molybdenum oxide;

1,4,5,8,9,12-hexaazatriphenylene-hexacarbonitrile (HAT-CN); and

a compound represented by Formula 221,

but embodiments of the present disclosure are not limited thereto:

In Formula 221,

R₂₂₁ to R₂₂₃ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group, wherein at least oneselected from R₂₂₁ to R₂₂₃ may have at least one substituent selectedfrom a cyano group, —F, —Cl, —Br, —I, a C₁-C₂₀ alkyl group substitutedwith —F, a C₁-C₂₀ alkyl group substituted with —Cl, a C₁-C₂₀ alkyl groupsubstituted with —Br, and a C₁-C₂₀ alkyl group substituted with —I.

[Emission Layer in Organic Layer 150]

When the organic light-emitting device 10 is a full-color organiclight-emitting device, the emission layer may be patterned into a redemission layer, a green emission layer, or a blue emission layer,according to a sub-pixel. In one or more embodiments, the emission layermay have a stacked structure of two or more layers selected from a redemission layer, a green emission layer, and a blue emission layer, inwhich the two or more layers contact each other or are separated fromeach other. In one or more embodiments, the emission layer may includetwo or more materials selected from a red light-emitting material, agreen light-emitting material, and a blue light-emitting material, inwhich the two or more materials are mixed with each other in a singlelayer to emit white light.

The emission layer may include a host and a dopant. The dopant mayinclude at least one selected from a phosphorescent dopant and afluorescent dopant.

In the emission layer, an amount of the dopant may be in a range ofabout 0.01 parts by weight to about 15 parts by weight based on 100parts by weight of the host, but embodiments of the present disclosureare not limited thereto.

A thickness of the emission layer may be in a range of about 100 Å toabout 1,000 Å, for example, about 200 Å to about 600 Å. When thethickness of the emission layer is within this range, excellentlight-emission characteristics may be obtained without a substantialincrease in driving voltage.

[Host in Emission Layer]

In one or more embodiments, the host may include a compound representedby Formula 301 below:

[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21)   <Formula 301>

In Formula 301,

Ar₃₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group ora substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xb11 may be 1, 2, or 3,

L₃₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xb1 may be an integer from 0 to 5,

R₃₀₁ may be selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group,a cyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a substituted or unsubstituted C₁-C₆₀ alkyl group, asubstituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted orunsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstitutedC₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkylgroup, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂),—B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), and —P(═O)(Q₃₀₁)(Q₃₀₂),

xb21 may be an integer from 1 to 5,

Q₃₀₁ to Q₃₀₃ may each independently be selected from a C₁-C₁₀ alkylgroup, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group, but embodiments of the presentdisclosure are not limited thereto.

In one embodiment, Ar₃₀₁ in Formula 301 may be selected from:

a naphthalene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, anindenoanthracene group, a dibenzofuran group, and a dibenzothiophenegroup; and

a naphthalene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, anindenoanthracene group, a dibenzofuran group, and a dibenzothiophenegroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂),—C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group,a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group, but embodiments of the present disclosureare not limited thereto.

When xb11 in Formula 301 is two or more, two or more Ar₃₀₁(s) may belinked via a single bond.

In one or more embodiments, the compound represented by Formula 301 maybe represented by Formula 301-1 or 301-2:

In Formulae 301-1 to 301-2,

ring A₃₀₁ to ring A₃₀₄ may each independently be selected from a benzenering, a naphthalene ring, a phenanthrene ring, a fluoranthene ring, atriphenylene ring, a pyrene ring, a chrysene ring, a pyridine ring, apyrimidine ring, an indene ring, a fluorene ring, a spiro-bifluorenering, a benzofluorene ring, a dibenzofluorene ring, an indole ring, acarbazole ring, a benzocarbazole ring, a dibenzocarbazole ring, a furanring, a benzofuran ring, a dibenzofuran ring, a naphthofuran ring, abenzonaphthofuran ring, a dinaphthofuran ring, a thiophene ring, abenzothiophene ring, a dibenzothiophene ring, a naphthothiophene ring, abenzonaphthothiophene ring, and a dinaphthothiophene ring,

X₃₀₁ may be O, S, or N-[(L₃₀₄)_(xb4)-R₃₀₄],

R₃₁₁ to R₃₁₄ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),—B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

xb22 and xb23 may each independently be 0, 1, or 2,

L₃₀₁, xb1, R₃₀₁, and Q₃₁ to Q₃₃ may be understood by referring tocorresponding description presented herein,

L₃₀₂ to L₃₀₄ may each independently be the same as defined in connectionwith L₃₀₁,

xb2 to xb4 may each independently be the same as defined in connectionwith xb1, and

R₃₀₂ to R₃₀₄ may each independently be the same as defined in connectionwith R₃₀₁.

For example, L₃₀₁ to L₃₀₄ in Formulae 301, 301-1, and 301-2 may eachindependently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, anaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pentacenyl group, a thiophenyl group, afuranyl group, a carbazolyl group, an indolyl group, an isoindolylgroup, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, anoxadiazolyl croup, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, abenzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinylgroup, an azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),—B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ are the same as described above.

In one embodiment, R₃₀₁ to R₃₀₄ in Formulae 301, 301-1, and 301-2 mayeach independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ are the same as described above.

In one embodiment, the host may include an alkaline earth-metal complex.For example, the host may be selected from a Be complex (for example,Compound H55), a Mg complex, and a Zn complex.

The host may include at least one selected from9,10-di(2-naphthyl)anthracene (ADN),2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN),9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN),4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene(mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), and Compounds H1 to H55,but embodiments of the present disclosure are not limited thereto:

[Phosphorescent Dopant Included in Emission Layer in Organic Layer 150]

The phosphorescent dopant may include the organometallic compoundrepresented by Formula 1.

The phosphorescent dopant may include an organometallic complexrepresented by Formula 401 below:

M(L₄₀₁)_(xc1)(L₄₀₂)_(xc2)   <Formula 401>

In Formulae 401 and 402,

M may be selected from iridium (Ir), platinum (Pt), palladium (Pd),osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu),terbium (Tb), rhodium (Rh), and thulium (Tm),

L₄₀₁ may be selected from ligands represented by Formula 402, and xc1may be 1, 2, or 3, wherein, when xc1 is two or more, two or more L₄₀₁(s)may be identical to or different from each other,

L₄₀₂ may be an organic ligand, and xc2 may be an integer from 0 to 4,wherein, when xc2 is two or more, two or more L₄₀₂(s) may be identicalto or different from each other,

X₄₀₁ to X₄₀₄ may each independently be nitrogen or carbon,

X₄₀₁ and X₄₀₃ may be linked via a single bond or a double bond, and X₄₀₂and X₄₀₄ may be linked via a single bond or a double bond,

A₄₀₁ and A₄₀₂ may each independently be selected from a C₅-C₆₀carbocyclic group or a C₁-C₆₀ heterocyclic group,

X₄₀₅ may be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₁)—*′,*—C(Q₄₁₁)(Q₄₁₂)-*′, *—C(Q₄₁₁)═C(Q₄₁₂)-*′, *—C(Q₄₁₁)=*′, or *═C═*′,wherein Q₄₁₁ and Q₄₁₂ may each independently be hydrogen, deuterium, aC₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenylgroup, a terphenyl group, or a naphthyl group,

X₄₀₆ may be a single bond, O, or S,

R₄₀₁ and R₄₀₂ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, asubstituted or unsubstituted C₁-C₂₀ alkyl group, a substituted orunsubstituted C₁-C₂₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃),—N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and—P(═O)(Q₄₀₁)(Q₄₀₂), wherein Q₄₀₁ to Q₄₀₃ may each independently beselected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a C₆-C₂₀ arylgroup, and a C₁-C₂₀ heteroaryl group,

xc11 and xc12 may each independently be an integer from 0 to 10, and

* and *′ in Formula 402 each indicate a binding site to M in Formula401.

In one embodiment, A₄₀₁ and A₄₀₂ in Formula 402 may each independentlybe selected from a benzene group, a naphthalene group, a fluorene group,a spiro-bifluorene group, an indene group, a pyrrole group, a thiophenegroup, a furan group, an imidazole group, a pyrazole group, a thiazolegroup, an isothiazole group, an oxazole group, an isoxazole group, apyridine group, a pyrazine group, a pyrimidine group, a pyridazinegroup, a quinoline group, an isoquinoline group, a benzoquinoline group,a quinoxaline group, a quinazoline group, a carbazole group, abenzimidazole group, a benzofuran group, a benzothiophene group, anisobenzothiophene group, a benzoxazole group, an isobenzoxazole group, atriazole group, a tetrazole group, an oxadiazole group, a triazinegroup, a dibenzofuran group, and a dibenzothiophene group.

In one or more embodiments, in Formula 402, i) X₄₀₁ may be nitrogen, andX₄₀₂ may be carbon, or ii) X₄₀₁ and X₄₀₂ may each be nitrogen at thesame time.

In one or more embodiments, R₄₀₂ and R₄₀₂ in Formula 402 may eachindependently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a phenyl group, a naphthyl group, a cyclopentyl group,a cyclohexyl group, an adamantanyl group, a norbornanyl group, and anorbornenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, anorbornanyl group, a norbornenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, anorbornanyl group, a norbornenyl group a phenyl group, a biphenyl group,a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinylgroup, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, atriazinyl group, a quinolinyl group, an isoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, acyclopentyl group, a cyclohexyl group, an adamantanyl group, anorbornanyl group, a norbornenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group; and

—Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁),—S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂), and

Q₄₀₁ to Q₄₀₃ may each independently be selected from a C₁-C₁₀ alkylgroup, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, and anaphthyl group, but embodiments of the present disclosure are notlimited thereto.

In one or more embodiments, when xc1 in Formula 401 is two or more, twoA401(s) in two or more L₄₀₁(s) may optionally be linked via X₄₀₇, whichis a linking group, or two A₄₀₂(s) in two or more L₄₀₁(s) may optionallybe linked via X₄₀₈, which is a linking group (see Compounds PD1 to PD4and PD7). X₄₀₇ and X₄₀₈ may each independently be a single bond, *—O—*′,*—S—*′, *—C(═O)—*′, *—N(Q₄₁₃)-*′, *—C(Q₄₁₃)(Q₄₁₄)-*′, or*—C(Q₄₁₃)=C(Q₄₁₄)-*′ (wherein Q₄₁₃ and Q₄₁₄ may each independently behydrogen, deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a biphenyl group, a terphenyl group, or a naphthyl group),but embodiments of the present disclosure are not limited thereto.

L₄₀₂ in Formula 401 may be a monovalent, divalent, or trivalent organicligand. For example, L₄₀₂ may be halogen, diketone (for example,acetylacetonate), carboxylic acid (for example, picolinate), —C(═O),isonitrile, —CN, and phosphorus (for example, phosphine or phosphite),but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the phosphorescent dopant may be selectedfrom, for example, Compounds PD1 to PD25, but embodiments of the presentdisclosure are not limited thereto:

[Fluorescent Dopant in Emission Layer]

The fluorescent dopant may include an arylamine compound or astyrylamine compound.

The fluorescent dopant may include a compound represented by Formula 501below:

In Formula 501,

Ar₅₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group ora substituted or unsubstituted C₁-C₆₀ heterocyclic group,

L₅₀₁ to L₅₀₃ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xd1 to xd3 may each independently be an integer from 0 to 3,

R₅₀₁ and R₅₀₂ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and

xd4 may be an integer from 1 to 6.

In one embodiment, Ar₅₀₁ in Formula 501 may be selected from:

a naphthalene group, a heptalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, and an indenophenanthrenegroup; and

a naphthalene group, a heptalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, and an indenophenanthrenegroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

In one or more embodiments, L₅₀₁ to L₅₀₃ in Formula 501 may eachindependently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, and a pyridinylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, and a pyridinylene group, each substituted withat least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group.

In one or more embodiments, R₅₀₁ and R₅₀₂ in Formula 501 may eachindependently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenylgroup, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃), and

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group,a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

In one or more embodiments, xd4 in Formula 501 may be 2, but embodimentsof the present disclosure are not limited thereto.

For example, the fluorescent dopant may be selected from Compounds FD1to FD22:

In one or more embodiments, the fluorescent dopant may be selected fromthe following compounds, but embodiments of the present disclosure arenot limited thereto:

[Electron Transport Region in Organic Layer 150]

The electron transport region may have i) a single-layered structureincluding a single layer including a single material, ii) asingle-layered structure including a single layer including a pluralityof different materials, or iii) a multi-layered structure having aplurality of layers including a plurality of different materials.

The electron transport region may include at least one selected from abuffer layer, a hole blocking layer, an electron control layer, anelectron transport layer, and an electron injection layer, butembodiments of the present disclosure are not limited thereto.

For example, the electron transport region may have an electrontransport layer/electron injection layer structure, a hole blockinglayer/electron transport layer/electron injection layer structure, anelectron control layer/electron transport layer/electron injection layerstructure, or a buffer layer/electron transport layer/electron injectionlayer structure, wherein for each structure, constituting layers aresequentially stacked from an emission layer. However, embodiments of thestructure of the electron transport region are not limited thereto.

The electron transport region (for example, a buffer layer, a holeblocking layer, an electron control layer, or an electron transportlayer in the electron transport region) may include a metal-freecompound containing at least one π electron-depleted nitrogen-containingring.

The “π electron-depleted nitrogen-containing ring” indicates a C₁-C₆₀heterocyclic group having at least one *—N═*′ moiety as a ring-formingmoiety.

For example, the “π electron-depleted nitrogen-containing ring” may bei) a 5-membered to 7-membered heteromonocyclic group having at least one*—N═*′ moiety, ii) a heteropolycyclic group in which two or more5-membered to 7-membered heteromonocyclic groups each having at leastone *—N═*′ moiety are condensed with each other, or iii) aheteropolycyclic group in which at least one of 5-membered to 7-memberedheteromonocyclic groups, each having at least one *—N═*′ moiety, iscondensed with at least one C₅-C₆₀ carbocyclic group.

Examples of the π electron-depleted nitrogen-containing ring include animidazole, a pyrazole, a thiazole, an isothiazole, an oxazole, anisoxazole, a pyridine, a pyrazine, a pyrimidine, a pyridazine, anindazole, a purine, a quinoline, an isoquinoline, a benzoquinoline, aphthalazine, a naphthyridine, a quinoxaline, a quinazoline, a cinnoline,a phenanthridine, an acridine, a phenanthroline, a phenazine, abenzimidazole, an isobenzothiazole, a benzoxazole, an isobenzoxazole, atriazole, a tetrazole, an oxadiazole, a triazine, a thiadiazole, animidazopyridine, an imidazopyrimidine, and an azacarbazole, but are notlimited thereto.

For example, the electron transport region may include a compoundrepresented by Formula 601:

[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21)   <Formula 601>

In Formula 601,

Ar₆₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group ora substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xe11 may be 1, 2, or 3,

L₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xe1 may be an integer from 0 to 5,

R₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁),—S(═O)₂(Q₆₀₁), and —P(═O)(Q₆₀₁)(Q₆₀₂),

Q₆₀₁ to Q₆₀₃ may each independently be a C₁-C₁₀ alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or anaphthyl group, and

xe21 may be an integer from 1 to 5.

In one embodiment, at least one of Ar₆₀₁(s) in the number of xe11 andR₆₀₁(s) in the number of xe21 may include the π electron-depletednitrogen-containing ring.

In one embodiment, ring Ar₆₀₁ in Formula 601 may be selected from:

a benzene group, a naphthalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, a dibenzofuran group, adibenzothiophene group, a carbazole group, an imidazole group, apyrazole group, a thiazole group, an isothiazole group, an oxazolegroup, an isoxazole group, a pyridine group, a pyrazine group, apyrimidine group, a pyridazine group, an indazole group, a purine group,a quinoline group, an isoquinoline group, a benzoquinoline group, aphthalazine group, a naphthyridine group, a quinoxaline group, aquinazoline group, a cinnoline group, a phenanthridine group, anacridine group, a phenanthroline group, a phenazine group, abenzimidazole group, an isobenzothiazole group, a benzoxazole group, anisobenzoxazole group, a triazole group, a tetrazole group, an oxadiazolegroup, a triazine group, a thiadiazole group, an imidazopyridine group,an imidazopyrimidine group, and an azacarbazole group; and

a benzene group, a naphthalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, a dibenzofuran group, adibenzothiophene group, a carbazole group, an imidazole group, apyrazole group, a thiazole group, an isothiazole group, an oxazolegroup, an isoxazole group, a pyridine group, a pyrazine group, apyrimidine group, a pyridazine group, an indazole group, a purine group,a quinoline group, an isoquinoline group, a benzoquinoline group, aphthalazine group, a naphthyridine group, a quinoxaline group, aquinazoline group, a cinnoline group, a phenanthridine group, anacridine group, a phenanthroline group, a phenazine group, abenzimidazole group, an isobenzothiazole group, a benzoxazole group, anisobenzoxazole group, a triazole group, a tetrazole group, an oxadiazolegroup, a triazine group, a thiadiazole group, an imidazopyridine group,an imidazopyrimidine group, and an azacarbazole group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a biphenyl group, a terphenyl group, a naphthyl group,—Si(Q₃₁)(Q₃₂)(Q₃₃), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group,a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

When xe11 in Formula 601 is two or more, two or more Ar601(s) may belinked via a single bond.

In one or more embodiments, Ar₆₀₁ in Formula 601 may be an anthracenegroup.

In one or more embodiments, the compound represented by Formula 601 maybe represented by Formula 601-1:

In Formula 601-1,

X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), and X₆₁₆ may be N orC(R₆₁₆), wherein at least one selected from X₆₁₄ to X₆₁₆ may be N,

L₆₁₁ to L₆₁₃ may each independently be the same as defined in connectionwith L₆₀₁,

xe611 to xe613 may each independently be the same as defined inconnection with xe1,

R₆₁₁ to R₆₁₃ may each independently be the same as defined in connectionwith R₆₀₁, and

R₆₁₄ to R₆₁₆ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group.

In one embodiment, L₆₀₁ and L₆₁₁ to L₆₁₃ in Formulae 601 and 601-1 mayeach independently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, anaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pentacenyl group, a thiophenyl group, afuranyl group, a carbazolyl group, an indolyl group, an isoindolylgroup, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, anoxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, abenzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinylgroup, and an azacarbazolyl group,

but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, xe1 and xe611 to xe613 in Formulae 601 and601-1 may each independently be 0, 1, or 2.

In one or more embodiments, R₆₀₁ and R₆₁₁ to R₆₁₃ in Formulae 601 and601-1 may each independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group; and

—S(═O)₂(Q₆₀₁) and —P(═O)(Q₆₀₁)(Q₆₀₂), and

Q₆₀₁ and Q₆₀₂ are the same as described above.

The electron transport region may include at least one compound selectedfrom Compounds ET1 to ET36, but embodiments of the present disclosureare not limited thereto:

In one or more embodiments, the electron transport region may include atleast one selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline(BCP), 4,7-dphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq,3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole(TAZ), and NTAZ:

A thickness of the buffer layer, the hole blocking layer, or theelectron control layer may be in a range of about 20 Å to about 1,000 Å,for example, about 30 Å to about 300 Å. When the thicknesses of thebuffer layer, the hole blocking layer, and the electron control layerare within these ranges, the electron transport region may haveexcellent hole blocking characteristics or electron controlcharacteristics without a substantial increase in driving voltage.

A thickness of the electron transport layer may be from about 100 Å toabout 1,000 Å, for example, about 150 Å to about 500 Å. When thethickness of the electron transport layer is within the range describedabove, the electron transport layer may have satisfactory electrontransport characteristics without a substantial increase in drivingvoltage.

The electron transport region (for example, the electron transport layerin the electron transport region) may further include, in addition tothe materials described above, a metal-containing material.

The metal-containing material may include at least one selected fromalkali metal complex and alkaline earth-metal complex. The alkali metalcomplex may include a metal ion selected from a Li ion, a Na ion, a Kion, a Rb ion, and a Cs ion, and the alkaline earth-metal complex mayinclude a metal ion selected from a Be ion, a Mg ion, a Ca ion, a Srion, and a Ba ion. A ligand coordinated with the metal ion of the alkalimetal complex or the alkaline earth-metal complex may be selected from ahydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, ahydroxy acridine, a hydroxy phenanthridine, a hydroxy phenyl oxazole, ahydroxy phenylthiazole, a hydroxy diphenyl oxadiazole, a hydroxydiphenylthiadiazole, a hydroxy phenylpyridine, a hydroxyphenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, aphenanthroline, and a cyclopentadiene, but embodiments of the presentdisclosure are not limited thereto.

For example, the metal-containing material may include a Li complex. TheLi complex may include, for example, Compound ET-D1 (lithium quinolate,LiQ) or ET-D2:

The electron transport region may include an electron injection layerthat facilitates electron injection from the second electrode 190. Theelectron injection layer may directly contact the second electrode 190.

The electron injection layer may have i) a single-layered structureincluding a single layer including a single material, ii) asingle-layered structure including a single layer including a pluralityof different materials, or iii) a multi-layered structure having aplurality of layers including a plurality of different materials.

The electron injection layer may include an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal compound, an alkalineearth-metal compound, a rare earth metal compound, an alkali metalcomplex, an alkaline earth-metal complex, a rare earth metal complex, orany combinations thereof.

The alkali metal may be selected from Li, Na, K, Rb, and Cs. In oneembodiment, the alkali metal may be Li, Na, or Cs. In one or moreembodiments, the alkali metal may be Li or Cs, but embodiments of thepresent disclosure are not limited thereto.

The alkaline earth metal may be selected from Mg, Ca, Sr, and Ba.

The rare earth metal may be selected from Sc, Y, Ce, Tb, Yb, and Gd.

The alkali metal compound, the alkaline earth-metal compound, and therare earth metal compound may be selected from oxides and halides (forexample, fluorides, chlorides, bromides, or iodides) of the alkalimetal, the alkaline earth-metal, and the rare earth metal.

The alkali metal compound may be selected from alkali metal oxides, suchas Li₂O, Cs₂O, or K₂O, and alkali metal halides, such as LiF, NaF, CsF,KF, LiI, NaI, CsI, or KI. In one embodiment, the alkali metal compoundmay be selected from LiF, Li₂O, NaF, LiI, NaI, CsI, and KI, butembodiments of the present disclosure are not limited thereto.

The alkaline earth-metal compound may be selected from alkalineearth-metal oxides, such as BaO, SrO, CaO, Ba_(x)Sr_(1-x)O (0<x<1), orBa_(x)Ca_(1-x)O (0<x<1). In one embodiment, the alkaline earth-metalcompound may be selected from BaO, SrO, and CaO, but embodiments of thepresent disclosure are not limited thereto.

The rare earth metal compound may be selected from YbF₃, ScF₃, Sc₂O₃,Y₂O₃, Ce₂O₃, GdF₃, and TbF₃. In one embodiment, the rare earth metalcompound may be selected from YbF₃, ScF₃, TbF₃, YbI₃, ScI₃, and TbI₃,but embodiments of the present disclosure are not limited thereto.

The alkali metal complex, the alkaline earth-metal complex, and the rareearth metal complex may include an ion of alkali metal, alkalineearth-metal, and rare earth metal as described above, and a ligandcoordinated with a metal ion of the alkali metal complex, the alkalineearth-metal complex, or the rare earth metal complex may be selectedfrom hydroxy quinoline, hydroxy isoquinoline, hydroxy benzoquinoline,hydroxy acridine, hydroxy phenanthridine, hydroxy phenyl oxazole,hydroxy phenylthiazole, hydroxy diphenyloxadiazole, hydroxydiphenylthiadiazole, hydroxy phenylpyridine, hydroxyphenylbenzimidazole, hydroxy phenylbenzothiazole, bipyridine,phenanthroline, and cyclopentadiene, but embodiments of the presentdisclosure are not limited thereto.

The electron injection layer may consist of an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal compound, an alkalineearth-metal compound, a rare earth metal compound, an alkali metalcomplex, an alkaline earth-metal complex, a rare earth metal complex, orany combinations thereof, as described above. In one or moreembodiments, the electron injection layer may further include an organicmaterial. When the electron injection layer further includes an organicmaterial, an alkali metal, an alkaline earth metal, a rare earth metal,an alkali metal compound, an alkaline earth-metal compound, a rare earthmetal compound, an alkali metal complex, an alkaline earth-metalcomplex, a rare earth metal complex, or any combinations thereof may behomogeneously or non-homogeneously dispersed in a matrix including theorganic material.

A thickness of the electron injection layer may be in a range of about 1Å to about 100 Å, for example, about 3 Å to about 90 Å. When a thicknessof the electron injection layer is within these ranges, satisfactoryelectron injection characteristics may be obtained without substantialincrease in driving voltage.

[Second Electrode 190]

The second electrode 190 may be disposed on the organic layer 150 havingsuch a structure. The second electrode 190 may be a cathode which is anelectron injection electrode, and in this regard, a material for formingthe second electrode 190 may be selected from metal, an alloy, anelectrically conductive compound, and a combination thereof, which havea relatively low work function.

The second electrode 190 may include at least one selected from lithium(Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium(Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver(Mg—Ag), ITO, and IZO, but embodiments of the present disclosure are notlimited thereto. The second electrode 190 may be a transmissiveelectrode, a semi-transmissive electrode, or a reflective electrode.

The second electrode 190 may have a single-layered structure, or amulti-layered structure including two or more layers.

[Description of FIGS. 2 to 4]

FIG. 2 is a schematic view of an organic light-emitting device 20according to an embodiment. The organic light-emitting device 20includes a first capping layer 210, the first electrode 110, the organiclayer 150, and the second electrode 190, which are sequentially stackedin this stated order. FIG. 3 is a schematic view of an organiclight-emitting device 30 according to an embodiment. The organiclight-emitting device 30 includes the first electrode 110, the organiclayer 150, the second electrode 190, and a second capping layer 220,which are sequentially stacked in this stated order. FIG. 4 is aschematic view of an organic light-emitting device 40 according to anembodiment. The organic light-emitting device 40 includes the firstcapping layer 210, the first electrode 110, the organic layer 150, thesecond electrode 190, and the second capping layer 220, which aresequentially stacked in this stated order.

Regarding FIGS. 2 to 4, the first electrode 110, the organic layer 150,and the second electrode 190 may be understood by referring to thedescription presented in connection with FIG. 1.

In the organic layer 150 of each of the organic light-emitting devices20 and 40, light generated in an emission layer may pass through thefirst electrode 110 and the first capping layer 210 toward the outside,wherein the first electrode 110 may be a semi-transmissive electrode ora transmissive electrode. In the organic layer 150 of each of theorganic light-emitting devices 30 and 40, light generated in an emissionlayer may pass through the second electrode 190 and the second cappinglayer 220 toward the outside, wherein the second electrode 190 may be asemi-transmissive electrode or a transmissive electrode.

The first capping layer 210 and the second capping layer 220 mayincrease external luminescence efficiency according to the principle ofconstructive interference.

The first capping layer 210 and the second capping layer 220 may eachindependently be an organic capping layer including an organic material,an inorganic capping layer including an inorganic material, or acomposite capping layer including an organic material and an inorganicmaterial.

At least one selected from the first capping layer 210 and the secondcapping layer 220 may each independently include at least one materialselected from carbocyclic compounds, heterocyclic compounds, amine-basedcompounds, porphyrine derivatives, phthalocyanine derivatives,naphthalocyanine derivatives, alkali metal complexes, and alkalineearth-based complexes. The carbocyclic compound, the heterocycliccompound, and the amine-based compound may be optionally substitutedwith a substituent containing at least one element selected from O, N,S, Se, Si, F, Cl, Br, and I. In one embodiment, at least one selectedfrom the first capping layer 210 and the second capping layer 220 mayeach independently include an amine-based compound.

In one embodiment, at least one selected from the first capping layer210 and the second capping layer 220 may each independently include thecompound represented by Formula 201 or the compound represented byFormula 202.

In one or more embodiments, at least one selected from the first cappinglayer 210 and the second capping layer 220 may each independentlyinclude a compound selected from Compounds HT28 to HT33 and CompoundsCP1 to CP5, but embodiments of the present disclosure are not limitedthereto:

Hereinbefore, the organic light-emitting device according to anembodiment has been described in connection with FIGS. 1 to 4, butembodiments of the present disclosure are not limited thereto.

Layers constituting the hole transport region, an emission layer, andlayers constituting the electron transport region may be formed in acertain region by using one or more suitable methods selected fromvacuum deposition, spin coating, casting, Langmuir-Blodgett (LB)deposition, ink-jet printing, laser-printing, and laser-induced thermalimaging.

When layers constituting the hole transport region, an emission layer,and layers constituting the electron transport region are formed byvacuum deposition, the deposition may be performed at a depositiontemperature of about 100° C. to about 500° C., a vacuum degree of about10⁻⁸ torr to about 10⁻³ torr, and a deposition speed of about 0.01 Å/secto about 100 Å/sec by taking into account a material to be included in alayer to be formed, and the structure of a layer to be formed.

When layers constituting the hole transport region, an emission layer,and layers constituting the electron transport region are formed by spincoating, the spin coating may be performed at a coating speed of about2,000 rpm to about 5,000 rpm and at a heat treatment temperature ofabout 80° C. to 200° C. by taking into account a material to be includedin a layer to be formed, and the structure of a layer to be formed.

[General Definition of Substituents]

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear orbranched aliphatic saturated hydrocarbon monovalent group having 1 to 60carbon atoms, and examples thereof include a methyl group, an ethylgroup, a propyl group, an isobutyl group, a sec-butyl group, atert-butyl group, a pentyl group, an isoamyl group, and a hexyl group.The term “C₁-C₆₀ alkylene group” as used herein refers to a divalentgroup having the same structure as the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a hydrocarbongroup having at least one carbon-carbon double bond in the middle or atthe terminus of the C₂-C₆₀ alkyl group, and examples thereof include anethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀alkenylene group” as used herein refers to a divalent group having thesame structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a hydrocarbongroup having at least one carbon-carbon triple bond in the middle or atthe terminus of the C₂-C₆₀ alkyl group, and examples thereof include anethynyl group, and a propynyl group. The term “C₂-C₆₀ alkynylene group”as used herein refers to a divalent group having the same structure asthe C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalentgroup represented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group),and examples thereof include a methoxy group, an ethoxy group, and anisopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalentsaturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, andexamples thereof include a cyclopropyl group, a cyclobutyl group, acyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The term“C₃-C₁₀ cycloalkylene group” as used herein refers to a divalent grouphaving the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to amonovalent monocyclic group having at least one heteroatom selected fromN, O, Si, P, and S as a ring-forming atom and 1 to 10 carbon atoms, andexamples thereof include a 1,2,3,4-oxatriazolidinyl group, atetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term“C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalentgroup having the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group” as used herein refers to amonovalent monocyclic group that has 3 to 10 carbon atoms and at leastone carbon-carbon double bond in the ring thereof and no aromaticity,and examples thereof include a cyclopentenyl group, a cyclohexenylgroup, and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylenegroup” as used herein refers to a divalent group having the samestructure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to amonovalent monocyclic group that has at least one heteroatom selectedfrom N, O, Si, P, and S as a ring-forming atom, 1 to 10 carbon atoms,and at least one carbon-carbon double bond in its ring. Non-limitingexamples of the C₁-C₁₀ heterocycloalkenyl group include a4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, anda 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylenegroup” as used herein refers to a divalent group having the samestructure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent grouphaving a carbocyclic aromatic system having 6 to 60 carbon atoms, and aC₆-C₆₀ arylene group used herein refers to a divalent group having acarbocyclic aromatic system having 6 to 60 carbon atoms. Non-limitingexamples of the C₆-C₆₀ aryl group include a phenyl group, a naphthylgroup, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, anda chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylenegroup each include two or more rings, the rings may be fused to eachother.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalentgroup having a carbocyclic aromatic system that has at least oneheteroatom selected from N, O, Si, P, and S as a ring-forming atom, inaddition to 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group”as used herein refers to a divalent group having a carbocyclic aromaticsystem that has at least one heteroatom selected from N, O, Si, P, and Sas a ring-forming atom, in addition to 1 to 60 carbon atoms.Non-limiting examples of the C₁-C₆₀ heteroaryl group include a pyridinylgroup, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, atriazinyl group, a quinolinyl group, and an isoquinolinyl group. Whenthe C₁-C₆₀ heteroaryl group and the C₁-C₆₀ heteroarylene group eachinclude two or more rings, the rings may be condensed with each other.

The term “C₆-C₆₀ aryloxy group” as used herein refers to —OA₁₀₂ (whereinA₁₀₂ is the C₆-C₆₀ aryl group), and a C₆-C₆₀ arylthio group used hereinindicates —SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group” as usedherein refers to a monovalent group (for example, having 8 to 60 carbonatoms) having two or more rings condensed with each other, only carbonatoms as ring-forming atoms, and no aromaticity in its entire molecularstructure. A detailed example of the monovalent non-aromatic condensedpolycyclic group is a fluorenyl group. The term “divalent non-aromaticcondensed polycyclic group” as used herein refers to a divalent grouphaving the same structure as the monovalent non-aromatic condensedpolycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” asused herein refers to a monovalent group (for example, having 1 to 60carbon atoms) having two or more rings condensed to each other, at leastone heteroatom selected from N, O, Si, P, and S, other than carbonatoms, as a ring-forming atom, and no aromaticity in its entiremolecular structure. An example of the monovalent non-aromatic condensedheteropolycyclic group is a carbazolyl group. The term “divalentnon-aromatic condensed heteropolycyclic group” as used herein refers toa divalent group having the same structure as the monovalentnon-aromatic condensed heteropolycyclic group.

The term “C₅-C₆₀ carbocyclic group” as used herein refers to amonocyclic or polycyclic group having 5 to 60 carbon atoms in which aring-forming atom is a carbon atom only. The term “C₅-C₆₀ carbocyclicgroup” as used herein refers to an aromatic carbocyclic group or anon-aromatic carbocyclic group. The C₅-C₆₀ carbocyclic group may be aring, such as benzene, a monovalent group, such as a phenyl group, or adivalent group, such as a phenylene group. In one or more embodiments,depending on the number of substituents connected to the C₅-C₆₀carbocyclic group, the C₅-C₆₀ carbocyclic group may be a trivalent groupor a quadrivalent group.

The term “C₁-C₆₀ heterocyclic group” as used herein refers to a grouphaving the same structure as the C₅-C₆₀ carbocyclic group, except thatas a ring-forming atom, at least one heteroatom selected from N, O, Si,P, and S is used in addition to carbon (the number of carbon atoms maybe in a range of 1 to 60).

In the present specification, at least one substituent of thesubstituted C₃-C₁₀ cycloalkylene group, the substituted C₁-C₁₀heterocycloalkylene group, the substituted C₃-C₁₀ cycloalkenylene group,the substituted C₁-C₁₀ heterocycloalkenylene group, the substitutedC₆-C₆₀ arylene group, the substituted C₁-C₆₀ heteroarylene group, thesubstituted divalent non-aromatic condensed polycyclic group, thesubstituted divalent non-aromatic condensed heteropolycyclic group, thesubstituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group,the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxygroup, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, thesubstituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ arylgroup, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substitutedmonovalent non-aromatic condensed polycyclic group, and the substitutedmonovalent non-aromatic condensed heteropolycyclic group may be selectedfrom:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), and —B(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidgroup or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), and —B(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁) and —P(═O)(Q₃₁)(Q₃₂), and

Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independently beselected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, aC₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroarylgroup, a monovalent non-aromatic condensed polycyclic group, amonovalent non-aromatic condensed heteropolycyclic group, a biphenylgroup, and a terphenyl group.

The term “Ph” as used herein refers to a phenyl group, the term “Me” asused herein refers to a methyl group, the term “Et” as used hereinrefers to an ethyl group, the term “ter-Bu” or “Bu^(t)” as used hereinrefers to a tert-butyl group, and the term “OMe” as used herein refersto a methoxy group.

The term “biphenyl group” as used herein refers to “a phenyl groupsubstituted with a phenyl group”. In other words, the “biphenyl group”is a substituted phenyl group having a C₆-C₆₀ aryl group as asubstituent.

The term “terphenyl group” as used herein refers to “a phenyl groupsubstituted with a biphenyl group”. In other words, the “terphenylgroup” is a phenyl group having, as a substituent, a C₆-C₆₀ aryl groupsubstituted with a C₆-C₆₀ aryl group.

*, *′, and *″ as used herein, unless defined otherwise, each refer to abinding site to a neighboring atom in a corresponding formula.

Hereinafter, a compound according to embodiments and an organiclight-emitting device according to embodiments will be described indetail with reference to Synthesis Examples and Examples. The wording “Bwas used instead of A” used in describing Synthesis Examples refers tothat an identical molar equivalent of B was used in place of A.

SYNTHESIS EXAMPLE Synthesis Example 1: Synthesis of Compound 1

(1) Synthesis of Intermediate [1-A]

2,6-dibromo-4-(tert-butyl)pyridine (1.0 eq), carbazole (3.0 eq),Pd₂(dba)₃ (0.2 eq), Sphos (0.4 eq), and K₃PO₄ (2.0 eq) were dissolved intoluene (0.5 M) and stirred at a temperature of 120° C. for 12 hours.After the reaction mixture was cooled to room temperature, an organiclayer was extracted therefrom three times by using dichloromethane andwater. The extracted organic layer was dried by using magnesium sulphateand concentrated, and column chromatography was used to obtainIntermediate [1-A] (yield: 65%).

(2) Synthesis of Intermediate [1-B]

Intermediate [1-A] (1.0 eq) was dissolved in tetrahydrofuran (0.5 M),n-buthylithium (1.2 eq) was slowly added thereto while stirring at atemperature of −78° C., and the reaction mixture was stirred for 2hours. 3-bromobenzaldehyde (1.2 eq) was slowly added thereto whilestirring at a temperature of −78° C., and the reaction mixture wasstirred at room temperature for 12 hours. An organic layer was extractedtherefrom three times by using dichloromethane and water. The extractedorganic layer was dried by using magnesium sulphate and concentrated,and column chromatography was used to Intermediate [1-B] (yield: 42%).

(3) Synthesis of Intermediate [1-C]

Intermediate [1-B] (1.0 eq) and DDQ (2.0 eq) were dissolved indichloromethane (0.5 M) and stirred at room temperature for 0.5 hours.An organic layer was extracted therefrom three times by usingdichloromethane and water. The extracted organic layer was dried byusing magnesium sulphate and concentrated, and column chromatography wasused to obtain Intermediate [1-C] (yield: 90%).

(4) Synthesis of Intermediate [1-D]

Magnesium turning (5.0 eq) was dissolved in tetrahydrofuran (0.5 M), andI₂ (0.01 eq) was added thereto. 2-bromo biphenyl (1.2 eq) was slowlyadded thereto while stirring the reaction mixture at room temperature,and was stirred for 3 hours. After the reaction mixture was cooled to atemperature of −78° C., Intermediate [1-C] (0.1 eq) dissolved intetrahydrofuran (0.5 M) was slowly added thereto while stirring thereaction mixture. The reaction mixture was heated to a temperature of70° C. and stirred for 12 hours. An organic layer was extractedtherefrom three times by using dichloromethane and water. The extractedorganic layer was dried by using magnesium sulfate and concentrated, andcolumn chromatography was used to obtain Intermediate [1-D] (yield:46%).

(5) Synthesis of Intermediate [1-E]

Intermediate [1-D] (1.0 eq) was dissolved in acetic acid (0.5 M) and 35%HCl aqueous solution (0.5 M) and stirred at a temperature of 120° C. for12 hours. After the reaction mixture was cooled to room temperature, andpH was adjusted to 6 to 7 by using 3N NaOH aqueous solution. An organiclayer was extracted therefrom three times by using dichloromethane andwater. The extracted organic layer was dried by using magnesium sulfateand concentrated, and column chromatography was used to obtainIntermediate [1-E] (yield: 55%).

(6) Synthesis of Intermediate [1-F]

Intermediate [1-E] (1.0 eq), imidazole (1.2 eq), CuI (0.01 eq), K₂CO₃(2.0 eq), and L-Proline (0.02 eq) were dissolved in dimethylsulfonate(0.1 M) and stirred at a temperature of 160° C. for 48 hours. After thereaction mixture was cooled to room temperature, an organic layer wasextracted therefrom three times by using dichloromethane and water. Theextracted organic layer was dried by using magnesium sulfate andconcentrated, and column chromatography was used to obtain Intermediate[1-F] (yield: 43%).

(7) Synthesis of Intermediate [1-G]

Intermediate [1-F] (1.0 eq) and iodomethane (3.0 eq) were dissolved inTHF (1.0 M) and stirred at a temperature of 70° C. for 12 hours. Afterthe reaction mixture was cooled to room temperature, an organic layerwas extracted therefrom three times by using dichloromethane and water.The extracted organic layer was dried by using magnesium sulfate andconcentrated, and column chromatography was used to obtain Intermediate[1-G] (yield: 83%).

(8) Synthesis of Compound 1

Intermediate [1-G] (1.0 eq), dichloro(1,2-dicyclooctadiene)platinum(Pt(COD)Cl₂) (1.1 eq), and sodium acetate (2.0 eq) were dissolved indioxane (0.1M) and stirred at a temperature of 120° C. for 72 hours.After the reaction mixture was cooled to room temperature, an organiclayer was extracted therefrom three times by using dichloromethane andwater. The extracted organic layer was dried by using magnesium sulfateand concentrated, and column chromatography was used to Compound 1(yield: 22%).

Synthesis Example 2: Synthesis of Compound 2

(1) Synthesis of Intermediate [2-A]

Intermediate [2-A] (yield: 41%) was synthesized in the same manner as inSynthesis of Intermediate [1-B], except that2,6-dibromo-4-(tert-butyl)pyridine was used instead of Intermediate[1-A], and benzaldehyde was used instead of 3-bromobenzaldehyde.

(2) Synthesis of Intermediate [2-B]

Intermediate [2-B] (yield: 67%) was synthesized in the same manner as inSynthesis of Intermediate [1-C], except that Intermediate [2-A] was usedinstead of Intermediate [1-B].

(3) Synthesis of Intermediate [2-C]

Intermediate [2-C] (yield: 43%) was synthesized in the same manner as inSynthesis of Intermediate [1-D], except that Intermediate [2-B] was usedinstead of Intermediate [1-C].

(4) Synthesis of Intermediate [2-D]

Intermediate [2-D] (yield: 43%) was synthesized in the same manner as inSynthesis of Intermediate [1-E], except that Intermediate [2-C] was usedinstead of Intermediate [1-D].

(5) Synthesis of Intermediate [2-E]

Intermediate [2-E] (yield: 44%) was synthesized in the same manner as inSynthesis of Intermediate [1-B], except that Intermediate [2-D] was usedinstead of Intermediate [1-A].

(6) Synthesis of Intermediate [2-F]

Intermediate [2-F] (yield: 62%) was synthesized in the same manner as inSynthesis of Intermediate [1-C], except that Intermediate [2-E] was usedinstead of Intermediate [1-B].

(7) Synthesis of Intermediate [2-G]

Intermediate [2-G] (yield: 43%) was synthesized in the same manner as inSynthesis of Intermediate [1-D], except that Intermediate [2-F] was usedinstead of Intermediate [1-C].

(8) Synthesis of Intermediate [2-H]

Intermediate [2-H] (yield: 47%) was synthesized in the same manner as inSynthesis of Intermediate [1-E], except that Intermediate [2-G] was usedinstead of Intermediate [1-D].

(9) Synthesis of Intermediate [2-I]

Intermediate [2-I] (yield: 52%) was synthesized in the same manner as inSynthesis of Intermediate [1-F], except that Intermediate [2-H] was usedinstead of Intermediate [1-E].

(10) Synthesis of Intermediate [2-J]

Intermediate [2-J] (yield: 86%) was synthesized in the same manner as inSynthesis of Intermediate [1-G], except that Intermediate [2-I] was usedinstead of Intermediate [1-F].

(11) Synthesis of Compound 2

Compound 2 (yield: 24%) was synthesized in the same manner as inSynthesis of Compound 1, except that Intermediate [2-J] was used insteadof Intermediate [1-G].

Synthesis Example 3: Synthesis of Compound 3

(1) Synthesis of Intermediate [3-A]

Intermediate [3-A] (yield: 27%) was synthesized in the same manner as inSynthesis of Intermediate [1-B], except that Intermediate [2-D] was usedinstead of Intermediate [1-A], and1-methyl-2-phenyl-1H-imidazole-4-carbaldehyde was used instead of3-bromobenzaldehyde.

(2) Synthesis of Intermediate [3-B]

Intermediate [3-B] (yield: 62%) was synthesized in the same manner as inSynthesis of Intermediate [1-C], except that Intermediate [3-A] was usedinstead of Intermediate [1-B].

(3) Synthesis of Intermediate [3-C]

Intermediate [3-C] (yield: 51%) was synthesized in the same manner as inSynthesis of Intermediate [1-D], except that Intermediate [3-B] was usedinstead of Intermediate [1-C].

(4) Synthesis of Intermediate [3-D]

Intermediate [3-D] (yield: 45%) was synthesized in the same manner as inSynthesis of Intermediate [1-E], except that Intermediate [3-C] was usedinstead of Intermediate [1-D].

(5) Synthesis of Compound 3

Compound 3 (yield: 31%) was synthesized in the same manner as inSynthesis of Compound 1, except that Intermediate [3-D] was used insteadof Intermediate [1-G].

Synthesis Example 4: Synthesis of Compound 4

(1) Synthesis of Intermediate [4-A]

2,6-dibromo-4-(tert-butyl)pyridine (1.0 eq), phenol (1.2 eq), CuI (0.01eq), K₂CO₃ (2.0 eq), and L-Proline (0.02 eq) were dissolved indimethylsulfonate (0.1 M) and stirred at a temperature of 160′ C. for 48hours. After the reaction mixture was cooled to room temperature, anorganic layer was extracted therefrom three times by usingdichloromethane and water. The extracted organic layer was dried byusing magnesium sulphate and concentrated, and column chromatography wasused to obtain Intermediate [4-A] (yield: 57%).

(2) Synthesis of Intermediate [4-B]

Intermediate [4-B] (yield: 29%) was synthesized in the same manner as inSynthesis of Intermediate [1-B], except that Intermediate [4-A] was usedinstead of Intermediate [1-A].

(3) Synthesis of Intermediate [4-C]

Intermediate [4-C] (yield: 62%) was synthesized in the same manner as inSynthesis of Intermediate [1-C], except that Intermediate [4-B] was usedinstead of Intermediate [1-B].

(4) Synthesis of Intermediate [4-D]

Intermediate [4-D] (yield: 49%) was synthesized in the same manner as inSynthesis of Intermediate [1-D], except that Intermediate [4-C] was usedinstead of Intermediate [1-C].

(5) Synthesis of Intermediate [4-E]

Intermediate [4-E] (yield: 47%) was synthesized in the same manner as inSynthesis of Intermediate [1-E], except that Intermediate [4-D] was usedinstead of Intermediate [1-D].

(6) Synthesis of Intermediate [4-F]

Intermediate [4-F] (yield: 54%) was synthesized in the same manner as inSynthesis of Intermediate [1-F], except that Intermediate [4-E] was usedinstead of Intermediate [1-E].

(7) Synthesis of Intermediate [4-G]

Intermediate [4-G] (yield: 81%) was synthesized in the same manner as inSynthesis of Intermediate [1-G], except that Intermediate [4-F] was usedinstead of Intermediate [1-F].

(8) Synthesis of Compound 4

Compound 4 (yield: 27%) was synthesized in the same manner as inSynthesis of Compound 1, except that Intermediate [4-G] was used insteadof Intermediate [1-G].

Synthesis Example 5: Synthesis of Compound 5

(1) Synthesis of Intermediate [5-A]

Intermediate [5-A] (yield: 51%) was synthesized in the same manner as inSynthesis of Intermediate [4-A], except that Intermediate [2-D] (1.0 eq)was used instead of 2,6-dibromo-4-(tert-butyl)pyridine, and3-bromophenol (1.2 eq) was used instead of phenol.

(2) Synthesis of Intermediate [5-B]

Intermediate [5-B] (yield: 52%) was synthesized in the same manner as inSynthesis of Intermediate [1-F], except that Intermediate [5-A] was usedinstead of Intermediate [1-E]

(3) Synthesis of Intermediate [5-C]

Intermediate [5-C] (yield: 77%) was synthesized in the same manner as inSynthesis of Intermediate [1-G], except that Intermediate [5-B] was usedinstead of Intermediate [1-F].

(4) Synthesis of Compound 5

Compound 5 (yield: 24%) was synthesized in the same manner as inSynthesis of Compound 1, except that Intermediate [5-C] was used insteadof Intermediate [1-G].

¹H NMR and LC-MS of Compounds synthesized according to SynthesisExamples 1 to 5 are shown in Table 1.

Synthesis methods of compounds other than Compounds shown in Table 1 mayalso be easily recognized by those of ordinary skill in the art byreferring to the synthesis mechanisms and source materials describedabove.

TABLE 1 Com- pound LC-MS No. ¹H NMR (CDCl₃, 400 MHz) found calc. 1 8.65(d, 1H), 8.55 (d, 1H), 8.15 (d, 1H), 7.90- 813.22 813.24 6.54 (m, 20H),3.67 (s, 3H), 1.32 (s, 9H) 2 8.61 (d, 1H), 7.87-6.60 (m, 25H), 6.49 (d,888.30 888.28 1H), 3.62 (s, 3H), 1.30 (s, 9H) 3 7.92-7.18 (m, 27H), 7.06(s, 1H), 3.73 (s, 888.21 888.28 3H), 1.29 (s, 9H) 4 8.66 (d, 1H),8.12-6.55 (m, 18H), 3.58 (s, 740.24 740.21 3H), 1.34 (s, 9H) 5 8.58 (d,1H), 8.03-6.27 (m, 18H), 5.67 (s, 740.19 740.21 1H), 3.69 (s, 3H), 1.31(s, 9H)

EVALUATION EXAMPLE

Quantum simulation was performed on i) A percentage of a tripletmetal-to-ligand charge transfer state (³MLCT), ii) a simulation value(λ_(max) ^(sim)) and an experiment value (λ_(max) ^(exp)) of awavelength of maximum emission, iii) an energy level of a tripletmetal-centered state (³MC), and iv) bond dissociation energy of an Natom of pyridine (Py) in a ligand and a metal center Pt of ComparativeExamples 1 to 5, and results thereof are shown in Table 2.

TABLE 2 ΔE_(HOMO-LUMO) Pt—Py bond (eV) λ_(max) ^(sim) (nm) λ_(max)^(exp) (nm) ³MLCT (%) dissociation energy (eV) Comparative 2.66 465.8094453 11.0 2.96 Compound 1 Comparative 1.73 714.005 — — — Compound 2Comparative 1.63 756.637 — — — Compound 3 Comparative 2.59 478.1594 48014.8 3.18 Compound 4 Comparatve 2.34 529.0396 515 15.1 3.01 Compound 5Compound 1 2.23 555.13 543 16.2 3.21 Compound 2 2.22 557.64 546 17.63.27 Compound 3 2.64 468.5062 458 17.1 3.10 Compound 4 2.51 493.5235 47915.7 3.07 Compound 5 2.93 422.5108 431 15.4 3.04 <Comparative Compound1>

<Comparative Compound 2>

<Comparative Compound 3>

<Comparative Compound 4>

<Comparative Compound 5>

EXAMPLE Example 1

As an anode, a Corning 15 Ω/cm² (1,200 Å) ITO glass substrate was cut toa size of 50 mm×50 mm×0.7 mm, sonicated with isopropyl alcohol and purewater each for 5 minutes, and then cleaned by exposure to ultravioletrays and ozone for 30 minutes. Then, the ITO glass substrate wasprovided to a vacuum deposition apparatus. 2-TNATA was vacuum-depositedon the ITO glass substrate to form a hole injection layer having athickness of 600 Å, and 4,4′-bis[N-(1-naphthyl)-N-phenylaminobiphenyl(NPB) was vacuum-deposited on the hole injection layer to form a holetransport layer having a thickness of 300 Å. Compound 1 (dopant) (weightratio of 10%) and 3,3-di(9H-carbazol-9-yl)biphenyl (mCBP) (host) wereco-deposited on the hole transport layer to form an emission layerhaving a thickness of 300 Å. Then,diphenyl(4-(triphenylsilyl)phenyl)-phosphine oxide (TSPO1) wasvacuum-deposited on the emission layer to form a hole blocking layerhaving a thickness of 50 Å. Then, Alq₃ was deposited on the holeblocking layer to form an electron transport layer having thickness of300 Å, an alkali metal halide LiF was deposited on the electrontransport layer to form an electron injection layer having a thicknessof 10 Å, and Al was vacuum-deposited to a thickness 3,000 Å (cathodeelectrode) to form an LiF/Al electrode, thereby completing themanufacture of an organic light-emitting device.

Examples 2 to 5

Organic light-emitting devices were manufactured in the same manner asin Example 1, except that Compounds 2 to 5 were each used instead ofCompound 1 as a dopant in forming an emission layer.

Comparative Examples 1 to 3

Organic light-emitting devices were manufactured in the same manner asin Example 1, except that Comparative Compounds 1, 4, and 5 were eachused instead of Compound 1 as a dopant in forming an emission layer.

The driving voltage, luminance, luminescence efficiency, and maximumemission efficiency of the organic light-emitting devices manufacturedaccording to Examples 1 to 5 and Comparative Examples 1 to 3 weremeasured at a current density of 50 mA/cm² by using Keithley SMU 236 anda luminance meter PR650, and an amount of time (lifespan) that lapsedwhen luminance was 50% of initial luminance (100%) was measured. Resultsthereof are shown in Table 3.

TABLE 3 Wavelength of Driving Current maximum voltage density LuminanceEfficiency emission Emission Emission layer (V) (mA/cm²) (cd/m²) (cd/A)(nm) color Example Compound 1 5.16 50 5351 10.7 543 Green 1 ExampleCompound 2 5.07 50 5603 11.2 546 Green 2 Example Compound 3 5.48 50 40338.07 458 Blue 3 Example Compound 4 5.24 50 4272 8.54 479 Blue 4 ExampleCompound 5 5.62 50 3995 7.99 431 Blue 5 Comparative Comparative 5.45 503910 7.82 453 Blue Example Compound 1 1 Comparative Comparative 6.85 503860 7.72 480 Blue Example Compound 4 2 Comparative Comparative 5.22 504556 9.11 515 Green Example Compound 5 3

From Table 3, it is confirmed that the green organic light-emittingdevices of Examples 1 and 2, in which the compounds according to one ormore embodiments are used in an emission layer as a dopant, have animproved driving voltage and increased luminescence efficiency, ascompared with the green organic light-emitting device of ComparativeExample 3.

It is confirmed that the blue organic light-emitting devices of Examples3 to 5, in which the compounds according to one or more embodiments areused in an emission layer as a dopant, have improved luminescenceefficiency, as compared with the blue organic light-emitting device ofComparative Example 1, and have a low driving voltage and highluminescence efficiency, as compared with the blue organiclight-emitting device of Comparative Example 2.

That is, when the compounds according to one or more embodiments areused in the organic light-emitting device, high color purity may beimplemented, and a suitable effect may be exhibited in terms of drivingvoltage and efficiency.

The organic light-emitting device including the organometallic compoundmay have a low driving voltage, high efficiency, a long lifespan, andhigh color purity.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

While one or more embodiments have been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope as defined by the following claims.

What is claimed is:
 1. An organic light-emitting device comprising: afirst electrode; a second electrode facing the first electrode; anorganic layer between the first electrode and the second electrode andcomprising an emission layer; and at least one organometallic compoundrepresented by Formula 1:

wherein, in Formula 1, M₁ is selected from platinum (Pt), palladium(Pd), copper (Cu), zinc (Zn), silver (Ag), gold (Au), rhodium (Rh),iridium (Ir), ruthenium (Ru), rhenium (Re), osmium (Os), titanium (Ti),zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), and thulium(Tm), ring A₁ to ring A₄ are each independently selected from a C₅-C₆₀carbocyclic group and a C₁-C₆₀ heterocyclic group, L₁ and L₄ are eachindependently selected from a single bond, *—O—*′, *—S—*′,*—C(R₅)(R₆)—*′, *—C(R₅)═*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═O)—*′,*—C(═S)—*′, *—C≡C—*′, *—B(R₅)—*′, *—N(R₅)—*′, *—P(R₅)—*′,*—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′, L₂ and L₃ are eachindependently selected from *—O—*′, *—S—*′, *—C(R₅)(R₆)—*′, *—C(R₅)═*′,*═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═O)—*′, *—C(═S)—*′, *—C═C*′,*—B(R₅)—*′, *—N(R₅)—*′, *—P(R₅)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and*—Ge(R₅)(R₆)—*′, at least one selected from L₂ and L₃ is selected from*—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′,and at least one pair of R₅ and R₆ selected from R₅ and R₆ in L₂ and R₅and R₆ in L₃ are linked to form a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup, a1 and a4 are each independently selected from 0, 1, 2, and 3,wherein the sum of a1 and a4 is 1 or more, when a1 is 0, ring A₁ andring A₂ are not linked with each other, and when a4 is 0, ring A₁ andring A₄ are not linked with each other, a2 and a3 are each independentlyselected from 1, 2, and 3, Y₁ to Y₄ are each independently selected froma carbon atom (C) and a nitrogen atom (N), B₁ to B₄ are eachindependently selected from a chemical bond, *—O—*′, and *—S—*′, R₁ toR₆ are each independently selected from hydrogen, deuterium, —F, —Cl,—Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a substituted orunsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, asubstituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁),—S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and —P(═S)(Q₁)(Q₂), twoneighboring substituents among R₁ to R₆ are optionally linked to form asubstituted or unsubstituted C₅-C₆₀ carbocyclic group or a substitutedor unsubstituted C₁-C₆₀ heterocyclic group, b1 to b4 are eachindependently an integer from 1 to 5, * and *′ each indicate a bindingsite to a neighboring atom, at least one substituent of the substitutedC₅-C₆₀ carbocyclic group, the substituted C₁-C₆₀ heterocyclic group, thesubstituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group,the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxygroup, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, thesubstituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ arylgroup, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substitutedmonovalent non-aromatic condensed polycyclic group, and the substitutedmonovalent non-aromatic condensed heteropolycyclic group is selectedfrom: deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, anda C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted withat least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂),—B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group; a C₃-C₁₀ cycloalkylgroup, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂),—B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ toQ₂₃, and Q₃₁ to Q₃₃ are each independently selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroarylgroup, a monovalent non-aromatic condensed polycyclic group, amonovalent non-aromatic condensed heteropolycyclic group, a biphenylgroup, and a terphenyl group.
 2. The organic light-emitting device ofclaim 1, wherein the first electrode is an anode, the second electrodeis a cathode, the organic layer comprises the organometallic compound,the organic layer further comprises a hole transport region between thefirst electrode and the emission layer and an electron transport regionbetween the emission layer and the second electrode, the hole transportregion comprises a hole injection layer, a hole transport layer, anemission auxiliary layer, an electron blocking layer, or any combinationthereof, and the electron transport region comprises a hole blockinglayer, an electron transport layer, an electron injection layer, or anycombination thereof.
 3. The organic light-emitting device of claim 1,wherein the emission layer comprises the organometallic compound.
 4. Theorganic light-emitting device of claim 3, wherein the emission layerfurther comprises a host, and an amount of the organometallic compoundcomprised in the emission layer is in a range of about 0.01 parts byweight to about 30 parts by weight based on 100 parts by weight of theemission layer.
 5. The organic light-emitting device of claim 3, whereinthe emission layer is configured to emit blue light or green lighthaving a wavelength of maximum emission in a range of 400 nm or more and600 nm or less.
 6. The organic light-emitting device of claim 2, whereinthe hole transport region comprises the electron blocking layer, and theelectron blocking layer comprises the organometallic compound; or theelectron transport region comprises the hole blocking layer, and thehole blocking layer comprises the organometallic compound.
 7. Theorganic light-emitting device of claim 2, wherein the hole transportregion comprises a p-dopant having a lowest unoccupied molecular orbital(LUMO) energy level of −3.5 eV or less.
 8. The organic light-emittingdevice of claim 2, wherein the electron transport region comprises aphosphine oxide-containing compound and/or a silyl-containing compound.9. An organometallic compound represented by Formula 1:

wherein, in Formula 1, M₁ is selected from platinum (Pt), palladium(Pd), copper(Cu), zinc (Zn), silver (Ag), gold (Au), rhodium (Rh),iridium (Ir), ruthenium (Ru), rhenium (Re), osmium (Os), titanium (Ti),zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), and thulium(Tm), ring A₁ to ring A₄ are each independently selected from a C₅-C₆₀carbocyclic group and a C₁-C₆₀ heterocyclic group, L₁ and L₄ are eachindependently selected from a single bond, *—O—*′, *—S—*′,*—C(R₅)(R₆)—*′, *—C(R₅)═*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═O)—*′,*—C(═S)—*′, *—C≡C*′, *—B(R₅)—*′, *—N(R₅)—*′, *—P(R₅)—*′,*—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′, L₂ and L₃ are eachindependently selected from *—O—*′, *—S—*′, *—C(R₅)(R₆)—*′, *—C(R₅)═*′,*═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′,*—B(R₅)—*′, *—N(R₅)—*′, *—P(R₅)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and*—Ge(R₅)(R₆)—*′, at least one selected from L₂ and L₃ is selected from*—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′,wherein at least one pair of R₅ and R₆ selected from R₅ and R₆ in L₂ andR₅ and R₆ in L₃ are linked to form a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup, a1 and a4 are each independently selected from 0, 1, 2, and 3,wherein the sum of a1 and a4 is 1 or more, when a1 is 0, ring A₁ andring A₂ are not linked with each other, and when a4 is 0, ring A₁ andring A₄ are not linked with each other, a2 and a3 are each independentlyselected from 1, 2, and 3, Y₁ to Y₄ are each independently selected froma carbon atom (C) and a nitrogen atom (N), B₁ to B₄ are eachindependently selected from a chemical bond, *—O—*′, and *—S—*′, R₁ toR₆ are each independently selected from hydrogen, deuterium, —F, —Cl,—Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a substituted orunsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, asubstituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁),—S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and —P(═S)(Q₁)(Q₂), twoneighboring substituents among R₁ to R₆ are optionally linked to form asubstituted or unsubstituted C₅-C₆₀ carbocyclic group or a substitutedor unsubstituted C₁-C₆₀ heterocyclic group, b1 to b4 are eachindependently an integer from 1 to 5, * and *′ each indicate a bindingsite to a neighboring atom, at least one substituent of the substitutedC₅-C₆₀ carbocyclic group, the substituted C₁-C₆₀ heterocyclic group, thesubstituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group,the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxygroup, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, thesubstituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ arylgroup, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substitutedmonovalent non-aromatic condensed polycyclic group, and the substitutedmonovalent non-aromatic condensed heteropolycyclic group is selectedfrom: deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, anda C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted withat least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂),—B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group; a C₃-C₁₀ cycloalkylgroup, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂),—B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ toQ₂₃, and Q₃₁ to Q₃₃ are each independently selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroarylgroup, a monovalent non-aromatic condensed polycyclic group, amonovalent non-aromatic condensed heteropolycyclic group, a biphenylgroup, and a terphenyl group.
 10. The organometallic compound of claim9, wherein ring A₁ to ring A₄ are each independently selected from abenzene group, a naphthalene group, an anthracene group, a phenanthrenegroup, an azulene group, a triphenylene group, a pyrene group, achrysene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalenegroup, a furan group, a thiophene group, a silole group, an indenegroup, a fluorene group, an indole group, a carbazole group, abenzofuran group, a dibenzofuran group, a benzothiophene group, adibenzothiophene group, a benzosilole group, a dibenzosilole group, anindenopyridine group, an indolopyridine group, a benzofuropyridinegroup, a benzothienopyridine group, a benzosilolopyridine group, anindenopyrimidine group, an indolopyrimidine group, a benzofuropyrimidinegroup, a benzothienopyrimidine group, a benzosilolopyrimidine group, adihydropyridine group, a pyridine group, a pyrimidine group, a pyrazinegroup, a pyridazine group, a triazine group, a quinoline group, anisoquinoline group, a quinoxaline group, a quinazoline group, aphenanthroline group, a pyrrole group, a pyrazole group, an imidazolegroup, a 2,3-dihydroimidazole group, a triazole group, a2,3-dihydrotriazole group, an oxazole group, an isoxazole group, athiazole group, an isothiazole group, an oxadiazole group, a thiadiazolegroup, a benzopyrazole group, a pyrazolopyridine group, a furopyrazolegroup, a thienopyrazole group, a benzimidazole group, a2,3-dihydrobenzimidazole group, an imidazopyridine group, a2,3-dihydroimidazopyridine group, a furoimidazole group, athienoimidazole group, an imidazopyrimidine group, a2,3-dihydroimidazopyrimidine group, an imidazopyrazine group, a2,3-dihydroimidazopyrazine group, a benzoxazole group, a benzothiazolegroup, a benzoxadiazole group, a benzothiadiazole group, a5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinolinegroup.
 11. The organometallic compound of claim 9, wherein ring A₃ is a6-membered ring comprising one or more N atoms, and one selected fromring A₁, ring A₂, and ring A₄ is a 5-membered ring comprising two ormore N atoms.
 12. The organometallic compound of claim 9, wherein ringA₃ is a group represented by Formula 2-2(1) and in which Y₁₅ is N, andring A₁, ring A₂, and ring A₄ are each independently selected fromgroups represented by Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25):

wherein, in Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25), Y₁₅ is acarbon atom (C) or a nitrogen atom (N), X₂₁ is N or C(R₂₁), X₂₂ is N orC(R₂₂), X₂₃ is N or C(R₂₃), X₂₄ is N or C(R₂₄), X₂₅ is N or C(R₂₅), X₂₆is N or C(R₂₆), X₂₇ is N or C(R₂₇), and X₂₈ is N or C(R₂₈), X₂₉ isC(R_(29a))(R_(29b)), Si(R_(29a))(R_(29b)), N(R₂₉), O, or S, X₃₀ isC(R_(30a))(R_(30b)), Si(R_(30a))(R_(30b)), N(R₃₀), O, or S, R₂₁ to R₃₀and R_(25a) to R_(30b) are each independently the same as defined inconnection with R₁ to R₄ in Formula 1, * indicates a binding site to B₁,B₂, B₃, or B₄, and *′ and *″ each indicate a binding site to aneighboring atom.
 13. The organometallic compound of claim 12, whereina4 is 0, ring A₁ and ring A₄ are each independently selected from groupsrepresented by Formulae 2-1(1) to 2-1(35), and ring A₂ is selected fromgroups represented by Formulae 2-2(1) to 2-2(25).
 14. The organometalliccompound of claim 9, wherein i) a2 and a3 are each 1, L₂ is selectedfrom *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and*—Ge(R₅)(R₆)—*′, L₃ is selected from *—O—*′, *—S—*′, *—C(R₅)(R₆)—*′, and*—N(R₅)—*′, and R₅ and R₆ in L₂ are linked to form a substituted orunsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstitutedC₁-C₆₀ heterocyclic group; ii) a2 and a3 are each 1, L₂ is selected from*—O—*′, *—S—*′, *—C(R₅)(R₆)—*′, and *—N(R₅)—*′, L₃ is selected from*—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′,and R₅ and R₆ in L₃ are linked to form a substituted or unsubstitutedC₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀heterocyclic group; or iii) a2 and a3 are each 1, L₂ and L₃ are eachindependently selected from *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′,*—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′, and at least one pair of R₅ and R₆selected from R₅ and R₆ in L₂ and R₅ and R₆ in L₃ are linked to form asubstituted or unsubstituted C₅-C₆₀ carbocyclic group or a substitutedor unsubstituted C₁-C₆₀ heterocyclic group.
 15. The organometalliccompound of claim 9, wherein at least one selected from L₂ and L₃ isselected from *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and*—Ge(R₅)(R₆)—*′, and at least one pair of R₅ and R₆ selected from R₅ andR₆ in L₂ and R₅ and R₆ in L₃ are linked to form a group represented byFormula 3:

wherein, in Formula 3, X₃₁ is selected from a single bond, *—O—*′,*—S—*′, *—Se—*′, *—C(R₃₃)(R₃₄)—*, *—C(R₃₃)═C(R₃₄)—*′, *—Si(R₃₃)(R₃₄)—*′,and *—Ge(R₃₃)(R₃₄)—*′, A₃₁ and A₃₂ are each independently selected froma C₆-C₃₀ carbocyclic group and a C₁-C₃₀ heterocyclic group, R₃₁ to R₃₄are each independently selected from hydrogen, deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂),—B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), Q₁ to Q₃ areeach independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group, a biphenylgroup, and a terphenyl group, b31 and b32 are each independentlyselected from 1, 2, 3, 4, 5, and 6, and * indicates a binding site to C,Si, P, or Ge.
 16. The organometallic compound of claim 9, wherein atleast one selected from L₂ and L₃ is selected from *—C(R₅)(R₆)—*′,*—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′, wherein at leastone pair of R₅ and R₆ selected from R₅ and R₆ in L₂ and R₅ and R₆ in L₃are linked to form a group represented by Formula 3A:

wherein, in Formula 3A, X₃₁ is selected from a single bond, *—O—*′,*—S—*′, *—Se—*′, *—C(R₃₃)(R₃₄)—*, *—C(R₃₃)═C(R₃₄)—*′, *—Si(R₃₃)(R₃₄)—*′,and *—Ge(R₃₃)(R₃₄)—*′, R₃₁ to R₃₄ are each independently selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazino group, a hydrazono group, asubstituted or unsubstituted C₁-C₆₀ alkyl group, a substituted orunsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstitutedC₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxygroup, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂),—C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), Q₁ to Q₃ are eachindependently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group, a biphenylgroup, and a terphenyl group, b31 and b32 are each independentlyselected from 1, 2, 3, and 4, and * indicates a binding site to C, Si,P, or Ge.
 17. The organometallic compound of claim 9, wherein each of B₁to B₄ is a chemical bond, Y₃ is N, and a bond between Y₃ and M₁ is acoordinate bond, i) Y₁, Y₂, and Y₄ are each C, one bond selected from abond between Y₁ and M₁, a bond between Y₂ and M₁, and a bond between Y₄and M₁ is a coordinate bond, and the others thereof are each a covalentbond; ii) Y₁ and Y₄ are each C, Y₂ is N, a bond between Y₂ and M₁ is acoordinate bond, and a bond between Y₁ and M₁ and a bond between Y₄ andM₁ are each a covalent bond; or iii) Y₁ is N, Y₂ and Y₄ are each C, abond between Y₁ and M₁ is a coordinate bond, and a bond between Y₂ andM₁ and a bond between Y₄ and M₁ are each a covalent bond.
 18. Theorganometallic compound of claim 9, wherein i) a1 is 1, and a4 is 0; orii) a1 is 0, and a4 is
 1. 19. The organometallic compound of claim 9,wherein the organometallic compound is represented by one of Formulae1-1 to 1-3:

wherein, in Formulae 1-1 to 1-3, L₂ and L₃ are each independentlyselected from *—O—*′, *—S—*′, *—C(R₅)(R₆)—*′, *—C(R₅)═*′, *═C(R₅)—*′,*—C(R₅)═C(R₆)—*′, *—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′, *—B(R₅)—*′,*—N(R₅)—*′, *—P(R₅)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, and*—Ge(R₅)(R₆)—*′, X₁ and X₂ are each independently selected from C, Si,P, and Ge, X₂₂ is N or C(R₂₂), X₂₃ is N or C(R₂₃), and X₂₄ is N orC(R₂₄), X₃₁ is selected from a single bond, *—O—*′, *—S—*′, *—Se—*′,*—C(R₃₃)(R₃₄)—*, *—C(R₃₃)═C(R₃₄)—*′, *—Si(R₃₃)(R₃₄)—*′, and*—Ge(R₃₃)(R₃₄)—*′, X₃₂ is selected from a single bond, *—O—*′, *—S—*′,*—Se—*′, *—C(R₃₇)(R₃₈)—*, *—C(R₃₇)═C(R₃₈)—*′, *—Si(R₃₇)(R₃₈)—*′, and*—Ge(R₃₇)(R₃₈)—*′, R₂₂ to R₂₄ and R₃₁ to R₃₈ are each independentlyselected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a substituted or unsubstituted C₁-C₆₀ alkyl group, asubstituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted orunsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstitutedC₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkylgroup, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂),—P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and—P(═S)(Q₁)(Q₂), b31, b32, b35, and b36 are each independently selectedfrom 1, 2, 3, and 4, M₁, ring A₁, ring A₂, ring A₄, L₁, L₄, a1, a4, Y₁to Y₄, B₁ to B₄, R₁, R₂, R₄, b1, b2, and b4 are each independently thesame as defined in connection with Formula
 1. 20. The organometalliccompound of claim 9, wherein the organometallic compound is selectedfrom Compounds 1 to 40: